Team:
Name Academic Discipline Team Position email
Dawn Salvatore MS/BS ISE Manager/Lead Engineer dms2774@rit.edu
Sarah Behling BS ISE Engineer sab0908@rit.edu
Jesseca Flaherty BS ME Engineer jlf4675@rit.edu
Natesha Greaves BS ISE Engineer ncg7009@rit.edu
Todd Pagliarulo BS ME Engineer tcp3496@rit.edu
Phil Trifeletti BS ME Engineer pst0803@rit.edu
Beth Sirianni BS ME Engineer ems1373@rit.edu
Professor Steibitz ISE Consultant phseie@rit.edu
Professor Nye ME Consultant ahneme@rit.edu
Introduction:

Located in Rochester, New York, Sentry Group is the world's leading supplier of fire-resistant and security storage containers, with a commitment to rigorous standards in design, manufacture and testing. Sentry has contacted Rochester Institute of Technology to work with a Senior Design group to evaluate and suggest improvements to their Step Up Chest manufacturing line.  

This report will outline the steps that Team 04019 has taken in the past 10 weeks to complete the Preliminary Design Requirements for Multidisciplinary Senior Design. It goes step by step through each of the facets that were taught in the classroom and how they were incorporated into this project. The facets that will be covered are: Needs Assessment, Concept Development, Feasibility Assessment, Design Objectives and Performance Specifications, Analysis of Problems and Synthesis of Design.

The step up chest work cell is comprised of three main areas:  the blow mold area, fill station, and assembly area.  The shells are blow molded and cut in the blow mold area.  The shells are then taken to the assembly area and placed into braces and put on the line.  They then proceed to the fill station, where one operator removes the safe from the line and fills it with insulation.  The wet anchor escutcheon plate is then placed on by another operator and the safe is put back on the line.  A conveyor takes the safe upstairs to cure.  Once cured, the safes are cleaned, labeled, and packed in the assembly area. 

Due to the broad nature of this project, the team has chosen to split up into three separate groups. Each group will look at a separate area to correctly evaluate them.  The three groups are the fill area, the snap fit plate, and the assembly area.

 

Customer Statement:

 

The Step Up Chest is a fire resistant/waterproof chest that is manufactured for distribution into the largest retail accounts.  This product is classified by Underwriter’s Laboratories (UL) for Fire-Resistance and its waterproof specifications are verified by Intertek Testing Services (ETL).  The Step Up Chest is manufactured on a work cell in our facility at 900 Linden Avenue, Rochester, New York.  The work cell consists of a blowmolder, insulation filling process, curing process, and an assembly line. The purpose of this project is to review the overall workcell operations and make critical improvements to increase the productivity to meet product demands for both delivery and costs.  The following should be considered when reviewing the work cells:

 

1.)    Overall process/Material Flow -  ensure all wasted steps are reduced or eliminated.

2.)    Product Design- consider improvements in design to reduce work content or reduce material costs.

3.)    Work cell design- Review individual workstations and design improvements to improve productivity and ergonomics.

 

The improvement team will be provided with the following:

 

1.)     A point of contact in both engineering and manufacturing to guide them through the Sentry manufacturing and documentation.

2.)    Necessary equipment and supplies.

3.)    Support from tool room staff as necessary

4.)     Money to make improvements and construct prototypes as necessary.

 

The improvement team should:

 

1.)     Develop priorities for areas of improvement based on data.

2.)     Outline which improvement activities they wish to implement and what will be suggestions for future implementation.

3.)     Execute the implementation with Sentry points of contact.  

 

Disciplines Involved:  Industrial Engineering (3 students- project scheduling/monitoring, product flow changes, ergonomics, facilities design), Mechanical Engineering (4 students- product/equipment design modifications).

Faculty Advisor:  Dr. Matthew Marshall, ISE

Project Sponsor: Bill Buchko, Manufacturing Engineering Manager, 381-4900 x2446

Facet 1. Needs Assessment

Project Mission Statement

The purpose of this project is to review the overall work cell operations and make critical improvements that will increase the productivity and to meet product demands for both delivery and cost.

     Product Description

The team will redesign the manufacturing work cell for the step up chest, specifically the H2100, H2300 and F2300 models. A multidisciplinary engineering team comprised of four mechanical engineers and three industrial engineers will perform the work cell redesign.

Scope Limitations

The mechanical engineers will implement product/equipment design modifications to facilitate process improvements. The industrial engineers will be responsible for project scheduling and monitoring, process flow changes, and improvements in ergonomics and facility design.

      Stakeholders

The Sentry Group and all of the operators producing this product plus the consumers, explicitly Wal-Mart Stores, are the stakeholders in this project.

      Key Business Goals

This project should produce an ideal working relationship with the Sentry Group and team group members. Both groups should be willing, attentive and dedicated to the project’s success. The design team will participate in a work cell environment and evaluate the manufacturing techniques.  If successful, there may be potential for future work employment in the Rochester area.

      Financial Analysis

Money to make improvements and construct prototypes will be provided as necessary. Also available will be Sentry department contacts to help with current Sentry processes and documentation, access to all necessary equipment and supplies, and full support from the tool room staff as necessary. An exact amount of funding available is dependent on the magnitude of the potential savings. The Sentry Group typically looks for a one-year pay back.

     Primary Market

The primary market of this project will be the Sentry Group located in Rochester, New York.

      Secondary Market

There is no secondary market in this project because the Sentry Group would not want their competitors to know their production methods.

      Order Qualifiers

This project will provide the Sentry Group with increased productivity through modifications made to their current work cell. This process will be more efficient and ergonomically correct which will make it possible to reduce production costs. The goal of this project is to increase the Hours per Unit produced by at least ten percent. The current HPU Is 0.1244. This would allow Sentry Group an annual savings of $56,000.


Facet 2. Concept Development - Brainstorming Ideas and Preliminary Sketches

 

    This brainstorming session consists of preliminary ideas to improve cost efficiency of the work cell in both productivity and financial standings.

 

Blow Mold Area

The blow molding area of the production line has two operators. Each operator has noticeable down time.  Two possible ways to eliminate this wasted time would be to have a single operator manning the area or to have additional tasks placed upon the two operators, such as folding the cardboard fillers and insert safes into the braces before sending the safes on. 

It appeared that the bottleneck in the production line was occurring at the blow molding area where the safes were piling up. A conveyor could automatically transport the newly blown safes to the assembly area where they would be placed in braces.

Sending the braces over to the blow molding area where they would be inserted and sent on to fill, skipping the assembly area all together, might help eliminate down time and bottleneck problems.

Fill

The 1150 and 1160 safe models are produced on the same production line as the H2100, H2300 and F2300 models. The brace used for the 1150 and 1160 safe family should be modified to eliminate operator injury.

 

During low production one operator is not sufficient to operate the current station – by moving the process inline only a single operator is needed and that operator would not be ergonomically taxed. 

 

Automating the fill station would eliminate human error and the problems that arise due to overfill, which has been problematic in the past.

 

Ecutcheon Plate

Design a snap fit escutcheon plate that will be added after curing in the assembly area.  This would effectively cut scrap costs.

A sensor would scan the safes before they went to cure, if there was a gap, it would loop it around the line for readjustments.  This would reduce a large amount of scrap caused by the escutcheon plate gap.

           

Assembly

A pallet lift could be added to the end of the assembly line to help increase efficiency.  It would be more ergonomically sound for the workers in that they would not have to continue to lift and bend with the safes.  This would free up time and create a better flow in the assembly area. 

 

A fillet will be added to the safe so that the superglue will no longer be needed.  This will cut some cost and will essentially free up some congestion in the assembly area for other improvements.

 

Finding an alternative escutcheon plate guard to replace the current cardboard piece used could be helpful. Folding the cardboard strips takes up value time in the assembly area that could be used in other productive manners or perhaps given to the blow molding area during their downtime. 

 

A substantial amount of money is being lost due to scrap.  Any scrap reductions could be beneficial.

 

Redesigning the assembly area could make it more ergonomically friendly and organized.  A few ideas include changing the labeling process and adding an automatic boxer to the line.

 

The current lighting system is dim and makes it difficult to see defects in the assembly area.  Adding additional lighting would help with the productivity of the workers in that area. 

 

A bottleneck seems to occur when the assembly area runs out of safes.  A light signal could be implemented so that the assembly area would flip a switch and indicate to the blow molding area that more safes are needed.  This would allow the line to flow better.

 

Miscellaneous         

 

The time to cure a safe could be reduced by adding coolers, which would speed up the total safe production time.  This would also reduce the amount of safes on hand and in inventory.

 

A second line would speed up production and allow for a larger quantity of safes to be produced during a given time.  

 

Reducing the material on hand would save the company money and allow them to invest it in other areas.

 

Adjust the current insulation mixture to make it make it cheaper. 

 

Analyze the parts to see if they can be redesigned more efficiently.

Customer Development Overview
 
This section consists of ranking the preliminary ideas to improve cost efficiency of the work cell in both productivity and financial standings.  Each member voted for four ideas, the top three were looked into further.
     
Concept Vote Tally Order of Rank
     
Blow Mold Area    
Operator Time 2  
Conveyor 4 2A
Brace Travel  
     
Fill Station    
Brace Change 1  
In Line Fill Station 4 2B
Automatic Fill Station 1  
     
Face Plate  
Snap Fit 4 2C
Gap Sensor    
   
Assembly    
Pallet Lift    
Super Glue 1  
Cardboard Packing 1  
Reduce Scrap    
Assembly Area Layout 7 1
     
Miscellaneous    
Cure Time    
Second Line    
Material on Hand 1  
Insulations 1  
FEA 1  
At this point in the project, the group of seven team members decided to split up into three groups to tackle the three areas identified. These areas are the inline fill station, a snap fit faceplate, and the overall effectiveness of the assembly area. The blow mold conveyor idea was disregarded due to lack of justification.  Each group went through the following assessments to determine which of the concepts they came up with would be best to be implemented.

 


Facet 3. Feasibility Assessment 

    This area will evaluate the feasibility and risks of the entire project. Each item has been scored from 1 to 5 with 1 having the lowest confidence level and 5 having the highest confidence level. By completing this, the areas for possible failure were identified and precautions were made how to avoid this.

 

Resource Feasibility 

The group felt that the pooled resources of the team, Sentry Safe, and RIT were sufficient skills to complete the project.

 

The Sentry tool room would provide any prototypes that are needed as well as implementing any designs. There are also a vast number of resources at RIT including faculty and computer programs.

 

With a group consisting of four Mechanical Engineers and three Industrial Engineers, the number of people should not be a problem.

 

The group would like to look into three major areas, which will require time management and staying on track.

 

Economic Feasibility

There is no set amount of funds, as long as the 10% savings is met.

 

The group was lacking the needed information to be sure that the project would meet its 10% goal within a year.

 

Schedule Feasibility

The group has been keeping up to date with in-class assignments and homework.

 

The main requirements will be met, but they may not be as well met as we would like them to be.

 

As long as the group keeps on schedule, there should be few problems meeting the CDR.

 

Technical Feasibility

L1 - Are you trying to break the laws of science? (NO)

L2 - Are fundamentally new inventions required? (NO)

L3 - Has a similar technology been used before (by anybody)? (YES)

L4 - Has the technology been demonstrated by our team? (YES)

L5 - Has the customer tested the technology? (NO)

 

Inline Fill Station

This action is performed to advance the trays to the automated part of the conveyor.  Since this is such a repetitive motion, a force gauge was used to determine if the amount of force applied to the safe was within the ergonomic standards to perform repetitively.  The amount of force needed to push the tray to the automatic conveyor section was ten pounds.  This amount of force is low and considered to not be an ergonomic issue.

 

In designing the inline fill station, it was necessary to take into consideration the method in which the trays would be vibrated.  The current system allows for the individual safes to be vibrated separately.  To assure that vibrating them for a longer period of time will not cause adverse affects on the fill, tests were run.  After vibrating for two minutes (much longer than normal), the results showed that there was no insulation separation proving that extra vibrating will not be an issue.

 

The current fill station design requires two operators at normal production speed.  During low production only one operator is needed, however, that operator has to maneuver around the fill station in a circular pattern not conducive to the workstation.  With the redesign, the inline fill station will allow for one person to manage the area, under normal production speed, while only moving from side to side.  Further time studies will be conducted to justify the elimination of an operator.

 

The fill heads of the station are currently pliable and are closed off by a clamp.  This method of turning the fill on or off allows the tubes to drip onto the safes which results in more cleaning once the safes arrive at the assembly area.  Redesigns of the fill heads and clamps were created, however they were not justified to be a contributor of reducing costs by 10% and therefore were deemed to be outside the scope of this project.

 

To eliminate dripping insulation on the safes, a drip pan was considered.  However, similar to the fill head design, this was not justifiable for cost reduction and was realized to be outside the scope of the project.

 

Snap Fit

Initially the goal was to save scrap costs by eliminating the gap between the escutcheon plate and the molded shell.  It was suggested that a snap fit plate would eliminate the gap issues.  A justification for using a snap fit plate was required prior to design.  

 

Due to the number of possible causes which were out of control, it was determined that the snap fit design would not solve the gap issue. 

 

While investing the snap fit concept, a greater benefit was discovered.  Currently Sentry uses a wet anchor process to adhere the escutcheon plate/lock to the safe.  Because the only quality check for this line happens in the assembly area, any defect forces the entire safe to be scrapped.  By using a snap fit design, the lock and faceplate can be saved from being scrapped for other safe defects. The key benefit lies with the fact that the faceplate with a lock consists of 20-25% of each unit’s cost.

 

Currently each faceplate/lock cost approximately $2.00 per unit. For the 2003 production year 15,000 units were scrapped due to defects. If the faceplate were snapped on after the quality check, $30,000 would have been saved in scrap costs alone. 

 

The cost to change over to a snap fit design has yet to be determined.  The costs will include the changes to the faceplate molds, the shell molds, and labor to make the changes. 

 

Possible future problems may arise inherent to the snap fit design. At this stage, a detailed analysis has yet to be performed, but initial concerns include:

 

Assembly Area

At first, it seemed to be a problem that the worker was reaching into a 40-inch high box to remove the safes. However, it was then found out that protocol was to cut a hole in the side of the box to easily access the safes towards the bottom of the box.

 

The boxed safes weigh 27 pounds each and it was seen as an area of concern when the boxes are moved from the conveyor to the pallet. An ergonomic study will be done using the NIOSH lifting formula to determine if this is truly an issue.

 

The workers in the assembly area do not wear earplugs. To be sure that this complies with OSHA Compliance Standards, a digital sound level meter will measure the levels of sound in the area.

 

There were complaints from an assembler that the lighting in his work area was not bright enough. This could easily be fixed by adding additional lighting.

           

The Escutcheon Guard is used as a shock absorber, so that the locks on the H2300 safes are not damaged in transition. They not only absorb the shock but they also keep the safe fixed in the box during transition. The current guard requires a strip of cardboard to be broken off from a full panel and folded to fit inside the box by the worker whenever he or she has time. It will be determined if this is the most cost and time effective product to protect the faceplate.


An automatic packing system, much like what is used at a different line at Sentry, could have a potential of packaging 12 to 17 safes per minute, depending on the model. Based on time studies, the current box and tape method produces 3 safes per minute. The low volume on the Step Up Chest line could not justify the need for an automatic packer because of its cost.

 

Currently there is no system in place to notify the blow molding area that the assembly area is low or out of empty safe cases. It takes approximately five minutes for a worker to notify a material transporter that he is out of safes, before they arrive at his area. With the light system, the material handler can be notified when the safes are low and the worker does not have to leave the area.

 

Having a label gun or automatic labeling machine is not feasible.  There are various stickers that are placed on the safe and to have a label gun for each of them would take up a great amount of space. Some of the stickers need precise placement and it is better done by hand. 

           

Using the Bill of Labor from Sentry, a simulation model was made to determine the correct number of workers that are needed in the assembly area. Currently, five workers are scheduled to staff the assembly area.


Facet 4. Establishing Design Objectives and Performance Specifications

Design Objectives 

The purpose of this section is to generate a series of questions that analyze the design objectives and performance specifications.  These objectives and performance specifications were determined through customer meetings, visits to Sentry, and through the evaluation of the needs assessment.

 

Performance Specifications 

A number of performance specifications need to be met in order for the project to be successful. The purpose of this section is to establish functional requirements in term of results and how well the design meets its goals. The performance specifications are listed as required for each subsection.

 

 

 


Facet 5. Analysis and Design Synthesis


Problem 1:  Making the Fill Station In-line

The existing fill station is capable of filling the step up chests (H2100, H2300, and F2300), along with the 1150 and 1160 models.  By revising the current station, it can be made more cost effective. 

The fill station requires two operators, one to remove the safe from the line and fill it, while the other puts the escutcheon plates onto the safe and back onto the line.  If one person is to run the station during low production, that person must fill the safe and walk around the station to put the escutcheon plate on.  Then they must walk back around to the original side to fill the next safe.  The time spent for the worker walking around the station makes it very difficult to justify having only one person work the station.  The following is a list of the problems associated with this fill station:

1.      The existing vibrating system is designed for one safe at a time off the tray.

2.      The existing system requires safes to be removed from the line for filling.

3.      The existing design requires two operators, one on each side of the station. 

4.      The existing system creates spillage due to placing filled safes back onto the line.

5.      The existing nozzles drip insulation even when they are clamped.

 

1.      What are the affects of vibrating both a filled safe with an empty safe, for an extended period of time, particularly while the empty safe is being filled?

2.      Can we make this station operable by one person?

3.      Will pushing the safe sideways create ergonomic issues?

 

1.      The components needed to improve the fill station will be made through the company’s tool room or will be sub-contracted to another machine shop.

2.      The money saved from creating the in-line fill station will pay for the improvements made.

 

To address the above problems associated with the filling station, the group determined that moving the station inline was a solution to the problem.  The scope of the project is to address the step up chests since it has the highest production numbers on the line.  Therefore in the proposed design the original filling station will stay in place to accommodate the 1150/1160 chests as proposed in the feasibility analysis (see appendix).

The design for the inline fill process is described in the following step by step process.  Please refer to the following figures in the Appendix that are referenced in the safe progression below.

1.      Two empty safes will be placed onto the redesigned tray with their braces. 

2.      The safes will come down the existing motorized line and stop by way of an electric eye (this process does not change from the existing system) (Y1 & Z1)

3.      While standing on the opposite side of the conveyor from the pre-existing system the operator will pull the tray forward, onto the dead vibrating rollers, until it stops at the first case stop.  (Y2 & Z2)

4.      The operator will fill the first safe using the pre-existing nozzle design

5.      The operator will lower the first case stop

6.      The operator will pull the tray forward; being sure that the second case stop is raised.  There will be a photo eye as a safety to disable the first case stop from rising while there is a tray above it.

7.      The tray will stop up against the second case stop. (Y3 & Z3)

8.      The operator will fill the second safe using the pre-existing nozzle design

9.      The operator will lower the second case stop

10.  The operator will advance the tray off of the vibrating rollers to non vibrating and dead rollers (Y4 & Z4)

11.  The operator will apply all four plates (two per safe) to the tops of the safes, covering the filling holes

12.  The operator will push the tray onto the pre-existing motorized rollers that will advance the tray to the elevating system

13.  Figure W – layout of fill station in relation to line

14.  Figure X – tray dimensions

15.  Figures Y1 through Y4 – side view of the tray progression

16.  Figures Z1 through Z 4 – top view of the tray progression

17.  Figure AA – description of parts

18.  Figure BB – bill of materials product prices

19.  Technical Data Package – product information

Alignment is an issue to be certain that the safes being filled in the above design will be underneath the fill heads so insulation is deposited into the safes.  The tray has been modified with bosses that are the same size as the cutouts on the bottom of the braces (Figure X), effectively aligning the safe to the tray.  Then the rails and the case stop on the conveyor will align the tray to the fill heads (Figures Z1–Z4).

 

In making the filling station inline it has been determined that 1.25 people are necessary to perform the filling and plating.  This was found through comparing the time study for the existing system to a proposed time study of the new system (Figure CC).  If the snap plate design is implemented, then it can be justified to only have one operator at this station.  We have assumed that the cost per one operator is $30,000 as directed by our customer.  Using this number and multiplying it by three shifts a day, there will be a savings of $90,000 a year for the company.

 

An experiment was done to determine if vibrating the safes for an extended period of time would create a problem with insulation separation.  The test consisted of 10 control safes and 10 experimental safes vibrated for 2 minutes.  After being left for five days to cure, the safes were cut in half.  The results revealed that no separation occurred, thus no adverse effects will occur in vibrating a full safe while the empty one is filling.

 

An ergonomic test was run to determine if the force required by the operator to advance the full safes along the dead rollers is feasible.  The results showed that the required force is not excessive for the operators.

 

Problem 2:  Reduce Waste with a Snap fit Escutcheon Plate

1.      First quality checkpoint is at the end of the line in the assembly area.

2.      The faceplate with the lock is a relatively expensive component.

3.      Eliminating face plate and lock from scrap with reduce scrap costs.

 

1.      How much the faceplate with lock cost per unit?

2.      How much it costs to change from the wet anchor design to a snap-fit design?

1.      Workers will detect defects prior to the addition of the snap-fit faceplate and lock.

2.      The savings on scrap will justify the cost to change the faceplate design.

 

1.      The H2100 breakdown of costs for the faceplate and lock are as follows:

 

Item Unit Cost
Flat key Lock $0.84
Faceplate Assembly $1.12
Total for Escutcheon Assembly $1.96

 

2.      Scrap Data:

 

  Unit Cost Number of Defects Total Scrap Savings
Half Hour Insulation $7.68 11,973 $23,394.60
Hour Insulation $11.06 3,210 $6,272.18

Grand Total Scrap Savings

$29,666.80

These savings do not include snap-fit change over cost.

 

Snap-fit design may cause new problems or completely eliminate existing problems.

 

Problem 3:  Ergonomics and Work Measurement of the Assembly Area

1.      Operators lift safes from the conveyor to a pallet without the use of a lifting aid.

2.      Currently, five operators are scheduled to work in the assembly area.

3.      The gluing operation for the safe will no longer be needed as they have already made design changes to allow for a press fit seal instead.

 

1.      Can we reduce the number of operators scheduled to work in the assembly area?

2.      Are the noise levels at an acceptable range to be exposed to for an eight-hour shift?

3.      Is lifting a safe from the conveyor to the pallet ergonomically correct?

4.      Can we create a signal as a communication device between the assembly and blow molding area?

5.      Are the lighting conditions sufficient in the assembly area?

 

When determining ergonomic issues using the NIOSH lifting equation, the 50th percentile will be used.

 

1.   Ergonomic Issues:

The CIMS – Material Handling Software was used to determine the results

Task Description:  Lifting Task for the H2300 safes from Conveyor to Pallet

The purpose of this study is to examine the forces exerted on two individuals from lifting the safe from a conveyor to a pallet. The first worker is 5’2” and weighs 120lbs. The second worker is 6’1” and 165lbs. The difference between these workers will be examined. The task is performed over an eight hour work day. Each worker is also responsible for packing the safes and taping them, so task variation exists. The packaged safe is 15 ½ x 6 ¾ x 12 ½ and weighs 27lbs. The pallet is 25” away from the conveyor and is 5 5/8 x 46 7/8 x 39 11/16. The conveyor is     35 1/8” high.

Both individuals lift the safe the same way to put them on the pallet. Each individual’s torso is turned approximately 45º to the right. They then turn fully in front of the pallet, so there torso is turned 0 º at the destination. Both individuals slightly bend their knees and bend forward to perform the task.

Due to the fact, this is a lifting task, the National Institute of Occupational Safety and Health guidelines were examined. They are used to examine the potential danger of forces exerted on the body by lifting the safe. The Material Handling Software is used to determine if this multi-task exceed the NIOSH lifting weight limits and the risk estimate for lifting related injuries and disorders. According to the NIOSH standards, if the lifting index is between one and three, the task poses an increase risk for some workers. If the lifting index is above three, many or most workers are at high risk of developing low-back pain and in injury.

This is the input for examined the NIOSH lifting guidelines in respect with the actual results found. Instead of examining the results of placing the safe at all 18 positions, one position on each level was examined. Significant control is required for this task.

 

Task Description:  Lifting Task for the H2300 safes from Conveyor to Pallet
Parameters for lift-lower task:

Level 1

Level 2
Average Object weight (lb) 27 27
Maximum Object weights (lb) 27 27
Hand Distance away from Body at Origin (in) 18 18
Hand Height at Origin (in) 41.38 41.38
Hand Distance away from Body at Destination (in) 17.5 17.5
Hand Height at Destination (in) 11.88 24.38
Back Rotation Angle at Origin 45º 45º
Back Rotation Angle at Destination
Frequency of task (lifts/min) 3 3
Work Time 6 Hours 6 Hours
Quality of Handles Fair Fair
Control is required at Task Destination (Y/N) Yes Yes

 

Below are is results from the Material Handling analysis.

Results: Lifting Task for the H2300 safes from Conveyor to Pallet

Task Number

Level 1 Level 2
Load weight (lb) 27 27
Task Frequency (F) 3 3
FIRWL 19.54 20.53
FM 0.55 0.55
STRWL 10.74 11.29
FILI 1.38 1.31
STLI 2.51 2.39
Cumulative Lifting Index  4.99

Due to the fact that the cumulative lifting index of 4.99 is above 3.0, most workers are at risk of developing lower back pain and injury.  This risk would increase when the workers are lifting double pack safes. To solve this problem, one option would be to use the vacuum hoist that is already in place in the assembly area. Another option would be to educate the assemblers on the proper lifting technique and provide them with back braces for lifting. However, back braces are not a substitute for proper ergonomics of material handling.  Finally, a rotating pallet lift could be purchased so that the assembler did not have to reach down to the lower levels of the pallet.  

Back injuries have a longer recovery period, are difficult to diagnose, and may occur over time. To avoid them, or to minimize the chance of risk, the individuals should use their legs during the lift, keep their arms close to the body, and avoid twisting their torso. As the horizontal distance between the load and the body increases, compressive forces in the spine increase. The load should be held as close to the body as possible without twisting the trunk. Also the individual’s feet should be place firmly on the ground.. The lift should occur approximately at the elbow level and safe should be lifted with both hands at all times.

To prove that these changes, would make a difference in this lifting situation. The task was re-examined with the Material Handling software. The load was moved closer to the body, and the vertical destination was elevated to the height of the conveyor (through the use of a adjustable pallet). Twisting of the torso was eliminated and the frequency of the task was reduced. Below are the details of this study. The multi-task was reanalyzed to calculate the effects of particular factors on the lifting index.

 

Task Description:  Lifting Task for the H2300 safes from Conveyor to Pallet Modified
Parameters for lift-lower task:

Level 1

Level 2
Average Object weight (lb) 27 27
Maximum Object weights (lb) 27 27
Hand Distance away from Body at Origin (in) 15 15
Hand Height at Origin (in) 41.38 41.38
Hand Distance away from Body at Destination (in) 15 15
Hand Height at Destination (in) 41.38 41.38
Back Rotation Angle at Origin
Back Rotation Angle at Destination
Frequency of task (lifts/min) 2 2
Work Time 6 Hours 6 Hours
Quality of Handles Fair Fair
Control is required at Task Destination (Y/N) Yes Yes

 

Results: Lifting Task for the H2300 safes from Conveyor to Pallet

Task Number

Level 1 Level 2
Load weight (lb) 27 27
Task Frequency (F) 3 3
FIRWL 31.09 31.09
FM 0.65 0.65
STRWL 20.21 20.21
FILI 0.86 0.86
STLI 1.33 1.33
Cumulative Lifting Index  1.92

 

Due to the fact that the cumulative lifting index of 4.99 is above 3.0, most workers are at risk of developing lower back pain and injury.  This risk would increase when the workers are lifting double pack safes. To solve this problem, one option would be to use the vacuum hoist that is already in place in the assembly area. Another option would be to educate the assemblers on the proper lifting technique and provide them with back braces for lifting. Finally, a rotating pallet lift could be purchased so that the assembler did not have to reach down to the lower levels of the pallet.  

A noise level assessment was done for the assembly area and fill area to make sure they met the United States Department of Labor Occupational Safety and Health Administration (OSHA) standards. Currently earplugs are not required for either area. According to OSHA, the sound level should measure no greater than 90 decibels in a particular area. The CEL-254 Digital Impulse Sound Level Meter used meets the ANSI standards for a sound level meter.  The meter was calibrated before and immediately after the measurements were taken.  The sound level was measured using the A-weighted scale, slow-response, and fast response meter. The A-weighted scale comprehends levels sensitive to the human ear.

The range settings for the sound level meter are:

Range Setting Frequency Weighting Display Range *Primary Linearity
A LO (low) A 30-100 dB 30-86 dB
A HI (high) A 65-135 dB 65-121 dB
Accuracy: +/- 1dB

Time weightings - Fast 125: milliseconds

                          - Slow: 1 second

*Note: that the lower reading is quoted as + 10dB on noise floor.  

 

 

 

 

For the test, 15 points were recorded for each area. The average noise level for the assembly area is 74.72 dBA and the average for the fill station area is 68.29 dBA. According to the OSHA standards, the level is both areas are well below the maximum limit, therefore earplugs are not necessary.

As far as the lighting in the assembly area is concerned, another overhead light should be placed above the first assembler who inserts and removes the safes into their braces.

 

2.   Escutcheon Plate Guard:

  <>

Cost Analysis for Escutcheon Plate Guard

 

Item Size (in.) Supplier Price (per unit) Price (per box)
Original 15 x 2 ½ x 7 -------

0.12

0.12

Sealed Air bags 14 x 16 Staples 2.64 2.64
Corrugated Cardboard Pad 14 x 12 KHL Express 0.19 0.19
Corrugated Cardboard Pad 14 x 5/32 x11 All Boxes Direct 0.44 0.44
Styrofoam Blocks

6 x 3 x 6

www.foamstore.com 0.85 1.70

Foam Roll

12 x ¼ x 12 www.papermart.com 1.22 1.22
Rapid Fill Air Bags 11 x 15 Uline 0.30 0.30
Styrofoam  “S” Peanuts 20 cu.ft. per bag Uline

------

(21.00/bag)

-----
Styrofoam “S” shaped peanuts 14 cu.ft. per bag www.papermart.com

------

(12.84/bag)

-----

Styrofoam figure “8” peanuts 14 cubic ft/bag www.papermart.com

-----

(12.21/bag)

-----

Bubble Wrap 12 x ½ x 12 Staples 0.46 0.92

 

Items such as tissue paper, shredded newspaper, Styrofoam sheets were not considered in this analysis. The escutcheon guards are the most economical solution and it was also determined that there was sufficient time for the packer to fold the cardboard guard throughout his shift; therefore, they will not be replaced with another item.

 

3.  Communication:

A light tower should be located along the aisle by the assembly area of the step up chest and in a location visible to the blow molding area. This will notify the material handler that more safes are needed in the assembly area. A tri-colored light would state whether there were no more safes, they were low, or there were enough at that time. The assembly area would control the light towers at both locations.

Through a time study, it was determined that it takes approximately five minutes for a worker in the assembly area to notify a worker in the blow mold area for more safes. By using a light system, the blow molder would be able to know when the assembly area needs more safes before they run out. This would allow the flow to run smoothly through the assembly area and prevent the bottleneck that occurs, due to the fact there are empty safe cases, but no safes to put in them.

The system consists of a switch by the assembly area and the status light(s) by the blow mold area. Whenever, the worker at the assembly area is out of safe, he/she can switch on the control; therefore, setting off one of the two lights at the blow mold area. The status light will be two colors: one for signaling blow mold area when supply is low and the other signal blow mold area when supply is completely finished. Below are estimates from three company’s stackable indicator lights.

Company Website  Item Number Cost
ATC www.automatictiming.com HYT-110-12 $69.50
OKsolar www.oksolar.com 113FS-RGA-N5 $87.25
Edward Signaling and Security System www.edwards-signals.com 102DMBS-N5 + 102LM-A $112.40

 

4.      Productivity Assessment:

A simulation model was performed testing the difference between four and five assembly area workers. It was found that there was no significant increase in the amount of safes produced when using five workers.  It is our recommendation that it is not cost effective to have more than four assembly workers. 

 

Facet 6. Reassessment and Changes

 

This facet was started after the project was carefully discussed with Sentry and the proposed designs and ideas were presented to them. From these changes, the final designs and recommendations could be completed and finally implemented. 

 

Inline Fill Area

 

At the end of the first ten weeks, a preliminary design of the new fill station was presented.  Since that time, the design has been re-evaluated and changed based on new information, feasibilities, and design stability.

 

The original design consisted of a fill head support system using threaded rods; however the rods would not provide the adequate support needed.  Two of the original redesigns included framework that could either hang from the above catwalk, or sit on the ground.  (Refer to Appendix C.1)  Hanging the system from the catwalk would include permanent welding that would not allow for future expansion possibilities, and any framework extending around the conveyor would inhibit operator movement.

 

For the final support system a length of 80/20 aluminum, attached to the support of the vibrating table, runs over the line to hold the fill heads.  Sentry commonly uses this material in building applications.  Due to Sentry’s familiarity with the material along with its strength and lightweight properties it was deemed the best material for the design.

 

The length of the conveyors from the proposed design was also re-evaluated.  The vibrating section of the conveyor was much longer then necessary; it was shortened to only vibrate the area of the conveyor needed while both safes are being filled.

 

The adjustments were made to show the proposed system’s new manning requirements, including the clarification of the tasks involved.  A recalculation of the estimated time was necessary due to an error in the previous time study where a task was double counted.

Escutcheon Plate

 

This section of the project was at such an early stage after the first ten weeks that it was decided that the new found information would be included in Facet 5. Therefore, there are no changes to the design of the snap-fit escutcheon plate as of right now.

 

Assembly Area

 

Sentry informed the group that something similar to the communication lighting system has already been installed in another area of the plant and is not being used. The workers did not adjust well to the system and it was felt that it would not help the situation of this line. With this information, the idea of a lighting notification system has diminished.

 

The Arena Simulation Model was looked at more extensively in the second 10 weeks. Sentry also informed the group that product line had changed from 3 shifts to 2 shifts. This not only affected the simulation model, but also the dollar amount that could potentially be saved by reducing a worker. With only two shifts, the potential savings dropped from an estimated $90,000 to $60,000.

 

Facet 7. Final Designs & Implementations 

This section contains the final designs and recommendations produced by the group for the Step-Up Chest line at Sentry Group. 

 

Inline Fill Station

 

The primary concern in this area was that the safes had to be removed from the production line in order to be filled with insulation.  The proposed design change involved moving the filling process onto the production line.

 

A mock up of the new system was created to perform a more accurate time study then was available previously.  The findings of this study showed that the average cycle time of the new system would be 52.994 seconds.  With the assembly area outputting a safe every 55 seconds, there will not be a bottleneck at the fill area.  This will allow for one operator to run this station at all times with a utilization rate of 95%.

 

The new design for the fill station will keep the safes on the line while they are being filled, and will only require a single operator. (Refer to Appendix C.2.1-3)  The section of rollers in front of the operator will have a vibrator attached to it and will be isolated from the rest of the line. The operator will pull a tray with two safes to the first case stop where the first safe is filled.  After the safe is full, the first case stop is lowered, and tray is advanced to the second case stop where the second safe is filled.  While the second safe is being filled it will be over the first case stop, in the way of a photo sensor that is used to deactivate the first case stop and prevent accidental rising.  After the second safe has been filled, the operator will advance the tray to place both sets of escutcheon plates onto the two safes.  The operator finishes the job by pushing the tray onto automatic rollers that send the safes to the curing area. 

 

 

Although the new design will be usable for the Step-Up Chests, there are other safes that run on the same production line that will not be able to use the new system.  The existing station will stay in place to be utilized when these safes are run.  The new system has been designed to accommodate the other safes on the production line once they receive necessary modifications.  Both the vibrating table and fill head supports have been designed ready for this change over in the future.

 Text Box: Proposed Lower Escutcheon Plate Design

By having the fill heads inline, three problems will be resolved.  The operators will no longer have to move the safes onto and off of the conveyor line addressing both ergonomic and timing problems. An inline system will also address the problem of spillage, since the safes will not be removed from the conveyor line at any point.  The new design involves a single operator facing the conveyor at all times, able to fill the safes and apply the escutcheon plates; this will eliminate the need for a second operator at this station.

 

In addition to other ways that the new fill station will save money in, elimination of an operator was the area investigated for monetary savings. The removal of an operator from this area will save Sentry $30,000 per shift a year.  With the Step-Up Chest line being run for two shifts a day there is a total savings of $60,000 a year.

 

Snap-fit 

The lower escutcheon plate has been successfully modeled for this design concept. This model is currently circulating amongst the suppliers of Sentry’s escutcheon plate for cost estimates. To complete this design, the upper escutcheon plate would have to be modeled, and the escutcheon assembly would have to be checked against the mating shell.  It is recommended that this concept be continued to fruition.

Text Box: Proposed Lower Escutcheon Plate Design 
 

 

 

 

 

 

 

 

Assembly Area

 

It is still recommended that something be done to improve the lifting procedures for moving the completed boxed safes to the pallet. It is up to Sentry to determine how they would like to see this done. As stated before, the options that are available are using the vacuum hoist that is currently installed but not used, investing in a rotating adjustable pallet lift table, requiring the worker to wear a lifting belt and/or educating the workers on the proper lifting techniques.  

After the first quarter of this project, another light was placed in the assembly area to help the workers see what they are doing better. 

A simulation model was developed using Arena: Rockwell Software to compare the quantity of safes that would be produced with four assembly workers versus five assembly workers. The model showed the ideal system, only including the Step-Up Chest and not including any delays or changeover time. Over the course of 25 days, the four worker model outputted 15,310 safes while the five worker model outputted 19,587. This equates to an approximate difference of ten safes per hour.  Even though the Resource Usage chart proves the assembly area needs can be met with four people, a cost analysis proved that it was not cost effective to remove the fifth worker from the area.

Although reducing the number of workers in the assembly area is not feasible as this time, it may be worthwhile to re-evaluate the situation once the new fill station is in place and if the snap-fit design is implemented.


Conclusion  

This document demonstrates all of the necessary facets given in the multidisciplinary design course plus two added facets that the group felt necessary. The customer’s needs were properly assessed, and concepts were developed to meet their needs.  From these concepts, the group determined the proper course of action to best achieve the goals.  Feasibility assessments were done for each concept to make sure that they were justifiable.   After determining the most feasible options, the concepts were further developed to meet design specification.  Preliminary analysis was completed and implementation is currently taking place.

 

The goal was to make the line ten percent more efficient and have a one year return on investment.  This goal has been met by reducing a person in the fill station.  Using an average salary of $30,000 a year, with the safes being run for two shifts, this produces a savings of $60,000 a year.  If the redesign of the escutcheon plate is pursued a savings of $90,000 can result.

 

 

Appendix A

 

A.1 Inline Fill Station Detailed Design Concepts

 

This session consists of detailed design concepts considered by the inline fill team. 

 

 

Table

 

 

§         Using a conveyor with separating paddles to advance the safes for filling.  The conveyor will circulate under the fill line.  There will be a guard protecting the operator from the rotating conveyor.

 

  

 

 

 

 

 

 

 

 

§         Separate the line to fit in a flat vibrating table.  The steps involved are removing the safe from the tray, filling the safe while it is being vibrated, and returning the safe to a tray on the other side of the fill station.  Case stops and guards will also be needed. 

 

 

 

 


 

·        “Grid Table” – Figure 3

 

§         Using a vibrating table that has flutes to fit in between existing rollers.  The table will lower out of the way when the safes are being advanced, and will rise when they are being filled, by use of a foot pedal.

 

 

 

 

 

 


 

·        Vibrating Roller Conveyor – Figure 4

 

§         A vibrator will be attached to the conveyor that is isolated from the line and floor.

 

 

 

 

 

 

Fill Lines

 

·        2 fill line – Figure 5

 

§         This involves two pairs of lines, directly over both safes on the tray, leading to the fill area.

 

 

 

 

 

 

 

 

·        1 fill line

 

§         There will be a single pair of fill lines leading to the new design

 

 

Nozzle

 

 

§         This would be in between the nozzle and the safe to catch any insulation that drips out of the nozzle.

 

 

 

 

 

 

 

 

 

 

·        Nozzle redesign

 

§         The nozzles could be redesigned to keep them from dripping

 

 

Tray Alignment

 

·        Cone Gate System – Figure 7

 

§         A gate that uses two cones at either end to engage the tray and hold it in placement under the fill nozzles

  
 

 

 

 

 

 

 

·        Case Stop – Figure 8

 

§         There will be two case stops in line the first will stop the tray aligning the first safe under the fill station.  The first stop will be lowered and the tray will advance until it hits the second stop.  Once the tray is aligned by the second stop the second safe will be able to be filled.

 

 

 

 

 

 

 

 


 

 

§         Guards will be used along the flow of the trays to align them along the width of the rollers

 

 

 

 

 

 

 

 

 


 

§         The braces have holes in the bottom of them that are currently being used to align the safes to the vibrating table – sitting directly under the fill station.  The safes can be aligned with the guards and the case stops – the trays will be redesigned having bosses to keep the safes aligned with the tray

 

 

 

 

 

 

 

 

 

 

Handle Heights

 

 

§         By applying lengthening rods to the pre-existing handles the operator would not need to raise his or her arms to operate the fill station

 

 

 

 

 

 

 

 

§         By raising the operator with a step, stool, or a platform he or she would not have to raise his or her arms as high as the current design requires

 


 

Future of the Current Fill Station

 

 

§         By making the current station removable it can be moved out of the way when the new station is being used and moved back into place when the 1150s and 1160s are being run on the line.

 

 

§         The current vibrating component can be attached to a tube – by inserting this tube into a hole in the new system the vibrating component will be able to pivot and rotate.  The safes will come down the line sitting on top of their braces.  The safes are then filled and rotated 90 degrees allowing them to slide onto a waiting tray further down the line.

 

 

 

 

 

 

 

 

§         Keeping the current fill station in place minimizes the time and effort needed with a product change over

 

Plate Dispensing

 

 

§         Another line uses half tubing to keep the plates easily accessible for the operators who need to apply them

 

 

§         The current system involves a rack that holds the plates in their shipping boxes – this is a good system that will be integrated into the new design


 

Inline Fill Station Detailed Feasibility Analysis

 

Table

 

·        “Paddle Wheel”

 

§         This will need a conveyor belt, which would work poorly in the environment.

§         Must be able to vibrate the entire tray (including two safes)

§         Vibrating the belt would be difficult

§         Must be able to advance perfectly no matter what the safe size

§         There is concern about vibration propagation on the belt, causing problems with the driving force

 

 

§         The operator must physically pick up the safe from the tray and place it on the table

§         The operator must physically pick up the full safe from the table and place it on the waiting tray

§         The operator must physically pick up the tray and move it from one side of the vibrating table to the other

 

 

§         The table and hydraulic system must be designed and built

§         Further research revealed tables made by manufacturers, but will be costly

§         Operators would have to wait for vibrating table to raise and lower to move trays on rollers

§         Must be able to vibrate the entire tray (including two safes)

§         Must be able to align for any safe size

 

 

§         Must be able to vibrate the entire tray

§         Decided to be the best system for best operator usage

 

Fill Lines

 

 

§         There is limited space for all 4 nozzles

§         The hopper needs to be redesigned to accommodate twice as much insulation needed

 


  • 1 fill line

§         With this design there will be a need for stopping the tray twice – to align each safe

§         There will not be a need to redesign the hopper to accommodate the insulation load

 

Nozzle

 

 

§         This would need to be cleaned regularly to keep buildup from occurring

 

 

§         Designing the nozzle system is to be considered a secondary project since the success of this project is not dependant on its completion.

 

Tray Alignment

 

 

§         Holes would need to be cut in the tray

§         Assuring that the gate is engaged at the appropriate time

 

 

§         Currently are used throughout plant, good way to control product flow

 

 

§         There are no real concerns here since they use this design already on this production line

 

 

§         Using the existing cut outs in the bottom of braces for safes, bosses on the tray will be used to align the brace to the tray.

 

Handles Height

 

 

§         Rods to move the them down will be in the way of the line, causing a complicated design to be implemented

§         Moving the handles down would give the operator the same visual range that is needed to fill the safes

 

 

§         Safety concerns include the need for railings on the platform and steps leading to it

§         Raising the operator would not give the operator the same visual range that is needed to fill the safes

§         Must keep same visual

 

Future of the Current Fill Station

 

 

§         Wheels could aid mobility, however, insulation buildup on floor makes this option not feasible.

§         Height alignment is crucial; therefore a removable station with fixed leg heights and variable floor heights (due to insulation buildup) makes this a difficult option.

§         The current system is supported by the conveyor line used in this line, to make it removable it must be able to stand freely

§         The current system will have to be “de-cemented” from the floor where it is currently encased

 

 

§         Component cannot be too heavy due to needs for removal

§         Pivoting the component can be compromised due to insulation buildup

 

 

§         This will involve designing the new station around the old one so that neither station is in the way when the other is being used.

§         This will allow Step-Up Chest to be run on inline fill and 1150/1160 safes to be run without significant modification to line

§         The fill lines will be the only thing that needs to be moved from one station to the other

 

Plate Dispensing

 

 

§         This will take longer then the current system since the plates will need to be emptied out onto the chute.

 

§         This will minimize the time it takes to refill the plate supply

 


 

Figure W

 

Layout of Fill Station in Relation to Product Line


 

Figure X

 

Tray Dimensions


 

Figure Y1 – Y4

 

Side View of Tray Progression

 

Figure Z1 –Z4

 

Top View of Tray Progression

 


Figure AA

 

Description of Parts

 

 

Item

Drawing Reference

Appendix

Details

Tray

Figure X

BOM - 9

There are two pairs of bosses on the tray. 

Each pair aligns a single safe brace to the tray

Vibrating Rollers

Called out - Figure Y

BOM - 3

The conveyor will be a three foot section

Rollers are 2" in diameter and separated by 3" on center

Each roller is 22" long - with

24" between rails of conveyor structure

Vibrator will be attached to a plate on the underside of the conveyor

The conveyor will be isolated by way of Elastomer Vibration Isolators

Vibrator

Called out - Figure Y

BOM - 1

Pneumatic vibrator

Requires a pressure of 30-90 psi

Vibration rate of 805 - 1160 Hz

Capacity of a flow rate from 2.4 - 11.6 CFM

Vibration Isolators

Called out - Figure Y

BOM - 6

Elastomer Vibration Isolators

1.5" Diameter with a 1.5" Height

Case Stop

Called out - Figure Y

BOM - 7

Solid piece of metal

Key way at a 45° angle to provide a 3" vertical rise

Linear actuator controlling the rise

Metal enclosure housing the stop and springs with the case stop failing up

Linear Actuator

Called out - Figure Y

BOM - 2

Dual separated chamber - for the raising and lowering

3" stroke with a 5/8" shaft

Compressed air cylinder

Photoelectric Switch

 

BOM - 5

Photoelectric sensor

Controller

 

BOM - 4

Logic controller for the photoelectric sensor

Case Stop Switch

TBA

TBA

Two way throw switch – TBA

Automatic Control Valve

TBA

TBA

To go before the first case stop -

Valve will close when the photo eye determines an obstruction

Detection of an obstruction will disable the operator control valve

Fill heads

Called out - Figure Y

BOM - 8

The existing fill head design will be used

Filling design will be suspended by rods - hung from the steel of the cat walk above

Aligning Guard

Called out - Figure Y

 

Material will be used to align the trays down the length of the progression

 


 

Figure BB – Bill of Materials

 

 

Bill of Materials

Part#

Part

Description

Stock #

Company

Quantity

Cost

1

Vibrator

Vibrator for Table

NTK 40 AL

Martin Engineering

1

$760.00

2

Compressed Air Cylinder

Linear Actuator for Case Stop

6498K359

McMaster

2

$17.12

3

Conveyor

2" Dia Roller Conveyor

 

McMaster

3

$584.25

4

Controller

Controller for Photoelectric Sensor

PLC-5 1771

Allen-Bradley

1

$700.00

5

Photoswitch

Photoelectric Sensor

42EF

Allen-Bradley

1

$135.00

6

Machinery Mount

Elastomeric Vibration Isolator

661

dB Engineering

4

$2.00

7

Case Stop

Machined Metal for Case Stop

 

Sentry

2

-

8

Fill Station

Build Fill Heads

 

Sentry

1

-

9

Tray

Tray with Aligning Nubs

 

Sentry

-

-

 

 

 

 

 

Total

$2,198.37

 

Figure CC

 

Time Study Results for Fill Station Operator One

 

 

 

 

 

 

 

 

 

 

Task

Time (sec)

 

 

 

 

 

 

Fill

16.88

 

 

 

 

 

 

Push

2.32

 

Average

Time (sec)

 

 

 

Get

3.57

 

Fill

15.28

 

 

 

Fill

14.57

 

Push

1.67

 

 

 

Push

2.16

 

Get

2.97

 

 

 

Get

3.41

 

 

19.92

Average Cycle Time

 

 

Fill

15.31

 

 

 

 

 

 

Push

1.4

 

39.84 seconds for 2 safes (1 tray)

 

 

Get

3.34

 

 

 

 

 

 

Fill

14.81

 

 

 

 

 

 

Push

1.47

 

New System

Time (sec)

 

 

 

Get

2.94

 

Fill

15.28

Will remain the same

 

Fill

14.84

 

Push

 - 

Counted as a second advancing in second half

 

Push

2

 

Get

2.97

Will remain the same even though different task will

 

Get

3.13

 

 

 

be needed

 

Fill

16.81

 

 

18.25

New Average Cycle Time

 

 

Push

1.97

 

 

 

 

 

 

Get

3

 

 

 

 

 

 

Fill

15

 

 

 

 

 

 

Push

1.75

 

36.5 seconds for 2 safes (one tray)

 

 

Get

3.15

 

 

 

 

 

 

Fill

15.53

 

 

 

 

 

 

Push

1.4

 

 

 

 

 

 

Get

2.72

 

 

 

 

 

 

Fill

13.35

 

 

 

 

 

 

Push

1.75

 

 

 

 

 

 

Get

2.97

 

 

 

 

 

 

Fill

14.72

 

 

 

 

 

 

Push

1.47

 

 

 

 

 

 

Get

2.88

 

 

 

 

 

 

Fill

14.9

 

 

 

 

 

 

Push

1.57

 

 

 

 

 

 

Get

2.41

 

 

 

 

 

 

Fill

14.66

 

 

 

 

 

 

Push

1.22

 

 

 

 

 

 

Get

2.75

 

 

 

 

 

 

Fill

15.44

 

 

 

 

 

 

Push

1.47

 

 

 

 

 

 

Get

2.66

 

 

 

 

 

 

Fill

15.21

 

 

 

 

 

 

Push

1.53

 

 

 

 

 

 

Get

2.68

 

 

 

 

 

 

Time Studies Results for Fill Station Operator Two

 

 

 

 

 

 

 

 

Task

Time (sec)

 

Average

Time (sec)

 

 

Swing Safe

1.54

 

Swings Safe

2.626

 

 

Grabs Plate

4.1

 

Grabs Plate

5.2

 

 

Fastens Plate

5.34

 

Fastens Plate

5.246

 

 

Safe to Tray

2.66

 

Safe to Tray

2.929

 

 

Grabs Plate

4.28

 

Advance

1.79

 

 

Swing Safe

1.65

 

Idle

5.067

 

 

Fastens Plate

4

 

 

 

 

 

Safe to Tray

2.56

 

 

 

 

 

Advance Tray

1.31

 

Bold Line Represents Cycle Breaks

 

Grabs Plate

4.41

 

 

 

 

 

Idle

5.5

 

19.762

Average Cycle Time

 

Swing Safe

2.28

 

 

 

 

 

Fastens Plate

4.47

 

39.524 seconds for 2 safes (1 tray)

 

Safe to Tray

4.13

 

 

 

 

 

Grabs Plate

4.94

 

 

 

 

 

Idle

5.38

 

New System

Time (sec)

 

 

Swing Safe

2.88

 

Swings Safe

 -

Removed

 

Fastens Plate

5.12

 

Grabs Plate

5.2

Same

 

Safe to Tray

2.81

 

Fastens Plate

5.246

Same

 

Grabs Plate

5.66

 

Safe to Tray

 -

Removed

 

Idle

6.82

 

Advance

3.58

Doubled

 

Swing Safe

2.41

 

Idle

 -

Removed

 

Fastens Plate

4.75

 

 

 

 

 

Safe to Tray

2.68

 

 

Items removed

 

Grabs Plate

6.34

 

14.546

Average Cycle Time

 

Swing Safe

3.72

 

 

 

 

 

Fastens Plate

4.75

 

 

 

 

 

Safe to Tray

3.1

 

29.092 seconds for 2 safes (1 tray)

 

Grabs Plate

8.6

 

 

 

 

 

Swing Safe

2.78

 

 

 

 

 

Fastens Plate

9.15

 

 

 

 

 

Safe to Tray

2.5

 

 

 

 

 

Advance Tray

2.49

 

 

 

 

 

Grabs Plate

3.87

 

 

 

 

 

Swing Safe

3.75

 

 

 

 

 

Fastens Plate

4.78

 

 

 

 

 

Safe to Tray

3.72

 

 

 

 

 

Grabs Plate

4.78

 

 

 

 

 

Idle

4.47

 

 

 

 

 

Swing Safe

2.72

 

 

 

 

 

Fastens Plate

5.22

 

 

 

 

 

Safe to Tray

2.16

 

 

 

 

 

Advance Tray

1.57

 

 

 

 

 

Grabs Plate

4.47

 

 

 

 

 

Idle

4.87

 

 

 

 

 

Swing Safe

2.53

 

 

 

 

 

Fastens Plate

4.88

 

 

 

 

 

Safe to Tray

2.97

 

 

 

 

 

Grabs Plate

5.75

 

 

 

 

 

                     

 

 

Analysis

 

 

 

 

 

 

 

 

Time is in seconds

 

 

 

 

 

 

 

 

Cycle Time for Assmebly Area

 

 

 

20.47

Cleaning

 

 

 

7.319

Return Empty Safe to Tray

 

 

 

27.789

 

 

 

 

 

 

 

 

 

55.578

Cycle Time for 2 safes (1 tray)

 

 

 

 

 

 

 

 

Cycle Time for Fill Station Operator 1

 

 

 

36.5

 

 

 

 

 

 

 

 

 

Cycle Time for Fill Station Operator 2

 

 

 

29.092

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

65.592

Combined Cycle Times

 

 

 

 

 

 

 

 

 

 

 

 

 

Since 65.592 seconds is greater than 55.578, there will be two people

needed to work the inline fill station

 

 

 

 

 

 

 

 

If a snap-fit plate was created then the cycle time for operator 2 would

be drastically reduced

 

 

 

 

 

 

 

 

3.58

Theoretical Cycle Time for Operator 2

 

 

 

Would only have to advance the trays

 

 

 

 

 

 

 

40.08

Theoretical Cycle Time with Snap-fit

 

 

 

 

 

 

 

This would decrease the fill station cycle time to 40.08 and be

 

less than the 55.578 cycle time of the assembly area, thus

 

making it feasible.

 

 

 

 

Appendix B

 

B.1  Snap-fit Escutcheon Plate Design Concepts

 

This session consists of design concepts considered by the snap-fit escutcheon plate team. 

 

Inside Snap / Lip

 

 

 

Slide

 

 

 

Incorporating 1100 Model Design

 

 

No Ribs

 

 

Ribs and Teeth

 

 

 

B.2  Snap-fit Escutcheon Plate Feasibility Analysis 

 

Overall Design Considerations

 

 

Inside Snap / Lip

 

 

Slide

 

 

Incorporating 1100 Model Design

 

 

No Ribs

 

 

Ribs and Teeth

 

 

 

 

 

Appendix C

C.1  Fill Station Fill Head Support Design Concepts

 

These are the designs that were considered for the fill head support system.

 

Threaded rod

 

 

 

Hanging truss

 

 

 

Ground supported

 

 

 

80/20 Final Design

 

 

 

 

C.2  Fill Station Final Drawings

 

C.2.1 Top View


C.2.2 Front View

 


C.2.3 Fill Head Support System