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Agenda for design activity. 1. Example 1: understanding requirements 2. Example 2: design 3. Example 3: real estate product 4. Example 4: structure product 5. Example 5: electrical product 6. Example 6: plumbing product 7. Optimizing design methods 8. Homework.
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Agenda for design activity 1. Example 1: understanding requirements 2. Example 2: design 3. Example 3: real estate product 4. Example 4: structure product 5. Example 5: electrical product 6. Example 6: plumbing product 7. Optimizing design methods 8. Homework
1. Example 1: understanding req • Purpose of example • Customer wants • Converting wants to spec and contract • Product contract • Product spec • Contractor wants • Contractor requirements 1. Example 1: understanding requirements
Purpose of example • Illustrate • Understand-requirements process • Customer wants vs requirements • Pseudo customer requirements • Validation • Tracing from spec to wants • Determining when understand-requirements activity is complete • Verification methods 1. Example 1: understanding requirements
Customer wants • W1: Live in a quiet place • W2: Have low maintenance costs • W3: Raise a garden • W4: Have room for family to visit • W5: Have adequate electricity • W6: Have a garage • W7: Cool in the evenings • W8: Pay $100,000 • W9: Obtain 6/1/03 1. Example 1: understanding requirements
Converting wants to spec & contract Wants W1: quiet W3:garden W5: electric W7: cool W9: close W2: low costs W4: family W6: garage W8: $100K S S S S S S S02: miles S03: 1/2 acre S11: water S10: 100 amps S08:east C3:close S01: <3yrs S04: no flood S05: low maint S12: equip works S06: 1800 S07: 3 bdr S09: garage C2:$100K C1: house & lot Spec Contract Wants flow to spec or contract directly or via studies 1. Example 1: understanding requirements
Product contract • C1: Provide house and lot that meet spec (ANA) • C2: Pay $100,000 (INS) • C3: Close on sale by 6/1/03 (INS) 1. Example 1: understanding requirements
Product spec (1 of 2) • S01: <3 years old (ANA) • S02: <10 & > 3 miles from town of 5000 people (INS) • S03: > 1/2 acre lot (INS) • S04: Does not flood (ANA) • S05: Low maintenance construction (INS) • S06: >1800 feet in air conditioning (INS) 1. Example 1: understanding requirements
Product spec (2 of 2) • S07: At least 3 bedrooms (INS) • S08: Master bedroom on east side (INS) • S09: Attached two-car garage (INS) • S10: >100 amperes electrical service (INS) • S11: > 11 gal/min from at least one faucet (TEST) • S12: Equipment works (DEMO) 1. Example 1: understanding requirements
Contractor wants Customer wants Contractor wants Designer profit Designer pride Government law 20% Happy buyer Meets code Contractor requirements Contractor wants create pseudo requirements in addition to customer requirements. These pseudo requirements can be considered to be part of the design. In this example, they don’t flow from the customer wants. 1. Example 1: understanding requirements
Contractor requirements • Wants • Ds1: 20 percent profit (INS) • Ds2: Make buyer happy (INS) • Lc1: Meets code (INS, DEMO) 1. Example 1: understanding requirements
2. Example 2: design • Purpose of example • Concept • Spec tree -- partitioning • Contractor design 2. Example 2: design
Purpose of example • Illustrate • Feasibility • Concept • Partitioning • Documentation 2. Example 2: design
Concept N Master Bedroom Bath Living Garage Kitchen Bedroom Bath Bedroom Storage Utility 2. Example 2: design
Spec tree -- partitioning House and lot Real estate Structure Electrical Plumbing 2. Example 2: design
Contractor design • Dd1: Plans • Floor plan • Elevations • Plumbing plan • Electrical plan • Foundation plan • Lot layout • Dd2: Flood analysis • Dd3: Cost and schedule 2. Example 2: design
3. Example 3: real estate product • Purpose of example • Real-estate flow down • Real-estate spec • Re-estate contract 3. Example 3: real-estate product
Purpose of the example • Illustrate • Acquire-products activity • Studies in flow down • Flow-up in requirements • Requirement for lower studies to support higher verification 3. Example 3: real-estate product
Real-estate flow down S01: < 3yrs S02: miles S03: 1/2 acre S04: doesn’t flood C2: $100,000 C3: close by 6/1/01 Ds1: 20% Dd2: flood analysis Dd3: Cost/sched study Dd1: Plans Rs1: miles Rs3: 1/2 acre Rs4: <3 yrs Rc1: land Rs5: survey Rs2: doesn’t flood Rc4: provide analysis Rc2: <$15,000 Rc3: close by 1/1/03 Product spec, product contract, and contractor-wants flow down directly and through studies to become the real estate spec and contract 3. Example 3: real-estate product
Real-estate spec • Rs1: <10 & > 3 miles from town of 5000 people (INS) • Rs2: Does not flood (ANA) • Rs3: > 1/2 acre (INS) • Rs4 <3 years (INS) 3. Example 3: real-estate product
Real-estate contract • Rc1: Provide land • Rc2: < $15,000 • Rc3: Close by 1/1/03 • Rc4: Provide flood analysis • Rc5: Provide survey Note: Contract and spec would be different if existing house were being purchased 3. Example 3: real-estate product
4. Example 4: structure product • Purpose of example • Structure flow down • Structure spec • Structure contract 4. Example 4: structure product
Purpose of example • Illustrate • Interface contract • Requirements from contractor design
Structure flow down S05: low maintenance S12: works Lc1: meets code Ds2: buyer happy C2: $100,000 C3: close by 6/1/03 Ds1: 20% Dd1: Plans Dd2: flood analysis Dd3: Cost/sched study Ss1: structure Sc1: meets design Ss2: brick Ss3: roof Ss4: paint Ss5: carpet Ss6: tile Ss7: colors Ss8: tile color Ss9: meets code Sc2: <$53,000 Sc3: close by 5/1/03 Sc4: coordinate Product spec, product contract, and contractor-wants flow down through studies to become the structure spec and contract 4. Example 4: structure product
Structure spec • Ss1: Meets design (INS) • Ss2: Brick (INS) • Ss3: 30-yr composition (INS) • Ss4: Long-lasting paint (INS) • Ss5: Nylon carpet except bath and kitchen (INS) • Ss6: Ceramic tile on all other interior floors (INS) • Ss7: White exterior paint, beige interior paint, beige carpet (INS) • Ss8: White tile (INS) • Ss9: Meets code (INS) 4. Example 4: structure product
Structure contract • Sc1: Provide structure • Sc2: <$53,000 • Sc3: Compete by 5/1/03 • Sc4: Coordinate with plumber and electrician 4. Example 4: structure product
5. Example 5: electrical product • Purpose of example • Electrical flow down • Electrical spec • Electrical contract 5. Example 5: electrical product
Purpose of example • Illustrate • Matching interface requirements 5. Example 5: electrical product
Electrical flow down S10: electrical S12: works Lc1: meets code C2: $100,000 C3: close by 6/1/03 Ds1: 20% Dd1: Plans Dd2: flood analysis Dd3: Cost/sched study Ec1: electrical Es1: meets design Ps2: electrical Ps3: meets code Ec2: <$4,000 Ec3: close by 5/1/03 Ec4: coordinate Product spec, product contract, and contractor-wants flow down through studies to become the electrical spec and contract 5. Example 5: electrical product
Electrical spec • Es1: Meets design (INS) • Es2: >100 amperes electrical service (INS) • Es3: Meets code (INS) 5. Example 5: electrical product
Electrical contract • Ec1: Provide electrical • Ec2: <$4,000 • Ec3: Complete by 5/1/03 • Ec4: Coordinate with structure 5. Example 5: electrical product
6. Example 6: plumbing product • Purpose of example • Plumbing flow down • Plumbing spec • Plumbing contract 5. Example 5: electrical product
Purpose of example • Illustrate • Verification by test
Plumbing flow down S11: water S12: works Dr1: meets code C2: $100,000 C3: close by 6/1/03 Ds1: 20% Dd1: Plans Dd2: flood analysis Dd3: Cost/sched study Pc1: plumbing Ps1: meets design Ps2: water Ps3: meets code Pc2: <$8,000 Pc3: close by 5/1/03 Pc4: coordinate Product spec, product contract, and contractor-wants flow down through studies to become the plumbing spec and contract 6. Example 6: plumbing product
Plumbing spec • Ps1: Meets design (INS) • Ps2: >100 gal/min from one faucet (TEST) • Ps3: Meets code (INS) 6. Example 6: plumbing product
Plumbing contract • Pc1: Provide plumbing • Pc2: <$8,000 • Pc3: Complete by 5/1/03 • Pc4: Coordinate with structure 6. Example 6: plumbing product
7. Optimizing design • Reason for discussing • Waterfall process • Modified waterfall process • Providing information when needed 7. Optimizing design
Reason for discussing (1 of 2) • Many approaches imply that requirements must be complete before design, design complete before build, and design of higher products complete before design of lower products 7. Optimizing design
Reason for discussing (1 of 2) • PBDA recognizes that not all requirements and design needs to be done before other activities can begin -- they can be build partially to allow other activities to proceed • PBDA is not the only approach that makes this recognition • This recognition shortens cycle time and reduces risk 7. Optimizing design
Waterfall process System i&t System design Box design Box i&t Software design Software i&t Waterfall process has classic V pattern. Steps are serial -- with each step finishing before the next starts 7. Optimizing design
Modified waterfall process Tasks start earlier System design System i&t Box design Box i&t Software design Software i&t Software and box developed in multiple builds Modified waterfall has shorter cycle time. It starts earlier & tasks develops in parallel often using multiple builds. 7. Optimizing design
Providing information when needed Percent of requirements complete 100 0 0 Percent of tasks to be developed 100 Concept Functions I/Fs Mechanical Test Design can start before requirements are complete 7. Optimizing design
8. Homework (1 of 2) • The customer wants to sell a line of lawn mowers that can cut Texas lawn grasses, requires partial assembly, and that costs less than $300 • Develop a design that satisfies the customer • 1. List the customer requirements (>0, <10) • 2. List pseudo customer requirements (0, <20) • 3. List the key items in the concept (>0, <20) • 4. List the key items in the design (>0, <20) 8. Homework
8. Homework (2 of 2) • Develop a design that satisfies the customer (continued) • 5. List key items in documentation (>0, <20) • 6. List the key items in the CDR (>0, <20) • Constraint of homework: List items shall be (>0, <30 words); no pictures 8. Homework