In the Systems Design Phase the team was looking to breakdown the roofing manufacturing system into functions, taking those functions and creating concepts that can be analysed for feasibility, risks, benchmarking and costs.
Content linked here should go in the Systems Level Design Documents
Team Vision for System-Level Design PhaseDuring the Phase the Team planned to accomplish these tasks:
- Increase understanding of the solution/systems requirements by creating a functional decomposition of the system.
- Research information about the local economy, as well as the materials and test procedures that will help to identify the ideal candidate mix and shape of the tile.
- Discover testing procedures as a means of testing identified engineering metrics.
- Research concrete testing standards.
- Research procedure used by previous MSD teams.
- Contact resources and tech experts to identify materials needs.
- Research where the materials can be bought from after mix is finalized.
- Contact known pumice tile manufacturer.
- Interview stakeholders that were missed in previous phase.
In this phase, the team has divided these goals into these themes and assignments:
- Matt will be leading and handling material requirements and testing.
- Derick will be leading project planning tasks, budget and sustainability analysis.
- Dan will be in leading contacting resources as well as researching firsthand by visiting El Sauce.
- Connor will be in leading research & design of manufacturing process
PurposeAs a means to find a concept for the roofing system, and the roofing system manufacturing process, the team worked on creating functional decompositions. These would provide the basic functions that are derived from the customer and engineering requirements, and highlight the difference functions and subfunctions.
Tile Focus Decomposition
Manufacturing Focus Decomposition
Benchmarking was used to look into several roof tiles consisting of different materials to determine what mix would be best to use. Based on our results the best would be a mix of the previous team (Team 17485) tile and the pumice tile.
Material Costs Analysis
Feasibility notes gathered while in Nicaragua:
- Gathering supplies: Pumice can be ordered cheaply in bulk from Masaya
- Crush Pumice: Pumice is ordered in chunks and must be crushed to about 1mm chunks
- Measure supplies: Measurement is done either by the bucket or the bag
- Mix supplies: Ricardo’s group mixed using large cement mixer; Mixing could easily be done using shovels and barrels/wheelbarrows
- Possible additional materials: Shredded plastic may be useful, but no real source for it; Plastic mesh from Durok may be useful; Styrofoam might provide better insulation, like in Durok
- Pour into mold: Ricardo’s group bought molds from US which lasted 5 years; Our team should follow this model, make vacuum-formed molds
- Shake mixture: Mixture was shaken for a few minutes in mold; This shook cement to bottom of mold, crucial for making top of tile impermeable; Motor should be bought to make shaker
- Leave tile in molds: Tiles left in mold for 1 day
- Remove tiles from molds and place in water pool: Tiles are left in water pool for 7 days
- Remove tiles from pool and allow to cure in the shade: Tiles cure in the shade for 21 days
- Sale: Sold for about $1 per tile
- Transportation: Transported via truck, relatively cheap
- Assembly: More supports will need to be bought for roofs; Wood difficult to get in Nicaragua
When preforming research, the team found that one of the most applicable ASTM standards was:
- ASTM-C293: This standard is considered a Center-point Flexural Test
Morphological Chart and Concept Selection
Each team member created their own process from the function concepts shown in the Morph chart above. A combined concept was also created by the team. Feasibility was taken into account when creating each concept. Also, the process described by Ricardo is listed alongside the team's concepts, this will be used as the selection datum.
Cost: A + indicates less cost, a - indicates more cost, and an S indicates the same cost as the datum process.
Time: A + indicates less time to produce a tile, a - indicates more time to produce a quality, and an S indicates the time to produce the tile is the same as the datum process.
Repeatability: This criteria was used to compare the ease of repeating the process. A + indicates the process is easier to repeat, a - indicates the process is harder to repeat, and an S indicates the repeatability is the same as the datum process.
Quality: This criteria was used to compare the quality of tile produced. A + indicates the tile is of higher quality, a - indicates the tile is of lesser quality, and an S indicates the tile is of the same quality as the datum process.
Number of Power Tools: A + indicates less power tools needed, a - indicates more power tools needed, and an S indicates the same number of power tools needed as the datum process.
Number of Hand Tools: A + indicates less hand tools needed, a - indicates more hand tools needed, and an S indicates the same number of hand tools needed as the datum process.
Production Rate: This criteria was used to compare the amount of tiles that can be made in one day. A + indicates more tiles, a - indicates less tiles, and an S indicates the same number of tiles can be produced as the datum process.
Number of Workers: A + indicates less workers needed, a minus indicates more workers needed, and an S indicates the same number of workers needed as the datum process.
Scalability: This criteria was used to compare the ability to increase the production rate of the process. A + indicates it's easier to scale, a - indicates it's harder to scale, and an S indicates it is the same ease to scale as the datum process.
PurposeThe Systems Architecture is an important part of the Systems Design Process. Not only does it help to create the differentiates the subsystems, but it also categories the function found into those subsystems. A Description of how the team created our System Architecture is provided below.
Design of ArchitectureBecause the Team's focus is the Manufacturing Process, the Systems Architecture was created in the form of a process flow chart, with subsystems being comprised of related process steps, with each step being linked to a few functions from the functional decomposition.
PurposeThe high level Flowchart is a tool that we chose to use to describe the steps that would be present in the process.
DescriptionFor the flowchart, the team decided to build off of the systems architecture. This allowed the team to keep the functions covered consistent. The process has four major parts, the "Order Generation", "Materials Purchase and Preparation", "Manufacturing Process" and "Transportation Process."
Daniel Zinobile's Research Trip to El Sauce
From October 6-10, Daniel Zinobile traveled to Nicaragua with Kellan Morgan. During this trip, Daniel:
- Researched the prices and availability of construction materials
- Researched the prices and availability of power tools and construction equipment
- Spoke with Alvaro, a local clay tile and brick manufacturer, learned about his manufacturing process and problems with the tiles
- Spoke with Pepe, the director of 4 Walls, learned about the installation of current zinc roofs, learned about problems with zinc roofs, learned about equipment and material availability, and asked questions about our current proposed design and manufacturing process
- Spoke with Ricardo, who worked with the pumice tile manufacturing operation, and learned about every aspect of the tile manufacturing process and possible ways to improve it
- Observed 4 walls houses that had been built, and houses that were to be replaced with 4 walls houses
- Conducted additional research for teams 18433 and 18434
- Learned about the culture of El Sauce and Nicaragua as a whole
Notes taken during this trip were collected and summarized in the document linked below.
Plans for next phase
Preliminary Detailed Design Project Plan
This project plan focuses primarily on:
- Getting physical samples for mix types
- Introducing pumice into mixtures
- Prototyping the process
- Budgeting and planning for materials
- Brainstorming concepts for exact machinery