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Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
MIME Capstone Design
Project Initial Phase Systems
System Analysis Functional Decomposition
Design Research
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Project Initial Phase
Develop Customer Requirements
Perform System Analysis / Functional Decomposition
Conduct Design Research
Customer Requirements
SA / FD
Existing Designs
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Develop Customer Requirements
Writing Good Requirements Requirements state something:
Necessary
Verifiable/Measurable – Note: Customer Requirements (CRs) need not be Engineering Requirements (ERs) must be
Attainable
and they state it clearly.
Common Problems Writing implementation (HOW) instead of requirements (WHAT)
Using incorrect terms
Using incorrect sentence structure or bad grammar
Over-specifying
Missing requirements
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Writing implementation (HOW) instead of requirements (WHAT)
Example:– The workstation shall include an RDM
hydraulic lift, adjustable-height work table. (IMPLEMENTATION)
The requirement should state WHAT is needed not HOW it is to be provided.
Solution: Ask the question: WHY do you need the requirement?
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Writing implementation (HOW) instead of requirements (WHAT)
Answers: Workers of various sizes will use the workstation.
A typical workpiece requires handwork about four inches above the surface supporting it.
By ergonomic guidelines, the workpiece should be slightly below elbow level.
This is real requirement: The workstation shall be adjustable so that the work
surface is 4 in below the elbow level of the worker.
It leaves lots of options open for implementation.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Using Incorrect Terms
Use of Terms:– Requirements use the word “shall”.– Statements of fact use “will”.– Goals use “should”.
Terms to avoid:– support– but not limited to– etc.– and/or
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Using Incorrect Sentence Structure Or Bad Grammar
Requirements should be easy to read and understand. Format:
– The system shall provide means to …– The system shall be capable of …
– The system shall weigh …
– Subsystem 2.1 shall provide means to ...– Subsystem 2.2 shall interface with …
Note: the name of the system and subsystem appears in these locations, if the system name is complex, use acronyms.
Guidelines: – Each “shall” should be followed by a single predicate, not by a list.– Should not be complicated by explanation of operations, design or other
information.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Unverifiable Requirements
Avoid ambiguous terms:– Minimize– Maximize– Rapid– User-friendly– Easy– Sufficient– Adequate– Quick
Be specific. – How rapid? 10 per hour, 5 per hour.– What is sufficient? 10 units, 100 units.– What is “user-friendly”?
If you are not sure yet (e.g., in CR phase), – enclose the term in asterisks (e.g., *rapid*, *minimize*).
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Over-specifying(Typically in the ER Phase)
Major cause of cost overruns and delivery time delays.
Ask the question why it is needed before writing it as a requirement.
Be aware of over stringent requirements– Allow for tolerances (i.e. if height of a table
is specified to be 1000 mm allow for variations, such as 1000 +/- 10mm)
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Missing Requirements
Use models and other elaboration tools to make sure every aspect of the system is specified.
Requirements Drivers (i.e., things to think about):– Functional – Reliability– Performance – Maintainability– Environment – Safety, Integrity– Facility – Regulatory– Transportation – Security– Deployment – Privacy– Training – Complexity, Usability– Personnel – User Safety, Usability, Operability
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
SMART: Guidelines For Checking Requirements
S Specific? Well defined and clear to anyone involved in the product/process.
M Measurable? Have a way of quantifiable measurement to know when the requirement is reached, or at least the potential for that. Some flexibility in Customer Requirements.
A Agreed Upon? Agreement between both you and your customer.
R Realistic? Within the availability of resources and knowledge.
T Time Based? Enough time to produce the desired result.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Project Initial Phase
Develop Customer Requirements
Perform System Analysis / Functional Decomposition
Conduct Design Research
Customer Requirements
SA / FD
Existing Designs
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Perform System Analysis / Functional Decomposition
System (Engineered) A collection of entities that interact to perform
some useful function Can be analyzed / decomposed into
subsystems to facilitate understanding, design. Entities may be
physical components or processes.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
System
System
Subsystem 1 Subsystem 2 Subsystem 3
Subsystem 2.1 Subsystem 2.1 Subsystem 2.1
System Analysis
Functional Decomposition
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Function
An activity or process performed to achieve some desired end. e.g.,
provide power (ME) manufacture Widgets (IE / MfgE)
For our purposesfunction ≈ process
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Perform System Analysis / Functional Decomposition (additional points)
To perform Functional Decomposition is to perform System Analysis (analyze a system) with consideration to what functions the subsystems perform, not just proximity of physical components.
For our purposes,
System Analysis ≈ Functional Decomposition
Note, “System Analysis” / “Functional Decomposition” can mean
the process of performing SA / FD
or the result of performing SA / FD.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
System Analysis / Functional Decomposition Result Representation
DiagramSystem Analysis
orFunctional Decomposition
orSystem Hierarchy (Diagram)
System Analysisor
Functional Decomposition
Outline/Hierarchy System
Subsystem 1
Subsystem 2 Subsystem 2.1 Subsystem 2.2 Subsystem 2.3
Subsystem 3
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
System Analysis / Functional Decomposition Example 1(Based on a past Capstone Design Project)
Rainwater Use Demonstration System
Catchwater Subsystem
Water Transfer Subsystem
Water Use Subsystem
Holding-Pump Conduits Pump
Pump-Use Conduits
Objective: A system to demonstrate how rainwater can be collected and utilized using only natural or human power.
Collection Subsystem
Holding Subsystem
etc.
etc.Analysis/Decomposition proceeds to sufficient level of detail -- without making design decisions too early.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
System Analysis / Functional Decomposition Example 1(Based on a past Capstone Design Project)
Rainwater Use Demonstration System
Catchwater Subsystem Collection Subsystem Holding Subsystem
Water Transfer Subsystem Holding-Pump Conduit Pump Pump-Use Conduits
Water Use Subsystem
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Project Initial Phase
Develop Customer Requirements
Perform System Analysis / Functional Decomposition
Conduct Design Research
Customer Requirements
SA / FD
Existing Designs
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Conduct Design ResearchIncluding Benchmarking
Goal: to identify existing designs, methods, “best practices” or “state-of-the-art” as ideas for your project's
system subsystems equipment processes procedures
Prerequisites: System Analysis / Functional Decomposition sources of research / benchmarking sites
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Systems/Subsystems To Research and/or Benchmark
Some examples (drawn from past and present system/process projects) manual recyclables/waste sorting systems safe furniture handling training materials safety audit processes compact hand tool storage systems applications processing systems optimal pickup/delivery schedule algorithms equipment test procedures & equipment processes & equipment to remove hardware from used/scrap lumber equipment to grind waste wood into salable material manufacturing cost modeling methods production scheduling algorithms, software barcode equipment and procedures process (vs. product) quality control methods food packaging equipment & processes
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Sources For Design Research Textbooks Course Notes Catalogs Past Projects Baldrige and Presidential Quality Award Winners Federal Agencies Internet Experts Trade Journals Scientific Publications Navy Best Manufacturing Practices database College/University libraries Consultants Professional Associations Companies & other organizations for site visits Companies & other organizations for Formal BenchmarkingNOTE: These sources may not address systems exactly
like the one you are to design!
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Design Research For Example 1
Rainwater Use Demonstration System
Catchwater Subsystem
Water Transfer Subsystem
Water Use Subsystem
Holding-Pump Conduits Pump
Pump-Use Conduits
Collection Subsystem
Holding Subsystem
etc.
etc.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
System Analysis / Functional Decomposition Example 2Process-Oriented
Wood Waste Conversion System
Receiving ConversionStorage &
Sale
Waste Disposal
Grinding Pelletizing
Objective: A system to convert used wood (waste from building/remodeling) to a salable product.
Sorting Hardware Removal
etc.
etc.Analysis/Decomposition proceeds to sufficient level of detail -- without making design decisions too early.
etc.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
System Analysis / Functional Decomposition Example 2Using Process Verb Phrase Convention
Convert Wood Waste
Receive Used Wood
Convert to Product
Store & Sell
Dispose of Waste
Grind Pelletize
Objective: A system to convert used wood (waste from building/remodeling) to a salable product.
Sort Remove Hardware
etc.
etc.
etc.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
System Analysis / Functional Decomposition Example 3From a Class Example
Assemble Widgets
Restock Parts Get Widget Parts
Assemble Parts
Secure Parts To Base
Release Assembled
Widget
Inspect Widgets
Objective: Assemble parts into a finished Widget.
Hold Widget Base For Assembly
Position Parts In Place
Analysis/Decomposition proceeds to sufficient level of detail -- without making design decisions too early.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
System Analysis / Functional Decomposition Example 3IDEF0 Representation
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Formal Benchmarking Distinction: involves site visits to outside companies,
organizations, to identify
alternative approaches
“best practices”
etc.
Steps to formal benchmarking
Prepare to benchmark (decide what to benchmark, understand current process)
Conduct research (collect information, who’s best? who to ask?)
Select who to benchmark
Collect and share information
Analyze, adapt, improve
These Benchmarking slides were adapted from Dr. Toni Doolen's 2008-9 Capstone Design lecture, which was adapted, in turn, from Norma Jo Greenlee, U.S. Patent and Trademark Office, Office of Quality Management.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Benchmarking Guidelines
Be specific. Be willing to share. Make a win-win proposal. Know the site. Send questions. Don’t go alone. Document.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Benchmarking Guidelines
Respect privacy. Dress appropriately. You can call. Say thanks—often! Follow up.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Types of Formal Benchmarking
Internal Benchmarking Competitive Benchmarking Functional Benchmarking Generic Benchmarking
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Internal Benchmarking
An approach to benchmarking where organizations learn from “sister” companies, divisions, or operating units.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Competitive Benchmarking
An approach to benchmarking that targets specific product designs, process capabilities, or administrative methods used by one’s direct competitors.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Functional Benchmarking
An approach to benchmarking that seeks information from the same functional area within a particular application or industry.
Open minds.Open doors.TM
School of Mechanical, Industrial, & Manufacturing Engineering
Generic Benchmarking
An approach to benchmarking that seeks process performance information from outside one’s own industry. Enablers are translated from one organization to another through the interpretation of their analogous relationship.
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