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The Importance of the Requirements Phase

The Importance of the Requirements Phase. Shuly Cooper. To Be Discussed. Product Quality – Definition The issues and their root cause Cost of Quality (or lack of it) A Tool – Quality Function Deployment (QFD) Briefly – More quality tools ► Inspections

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The Importance of the Requirements Phase

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  1. The Importance of the Requirements Phase Shuly Cooper

  2. To Be Discussed • Product Quality – Definition • The issues and their root cause • Cost of Quality (or lack of it) • A Tool – • Quality Function Deployment (QFD) • Briefly – • More quality tools ► Inspections • ► Iterative/incremental dev. (small deliverables) • The deliverables of the Requirements Phase

  3. Product Quality - Definition • 19451980s • “Higher Accuracy & Reliability” • The Era of Statistical Process Control (SPC) • Dr. W. Edward Deming • Dr. Peter F. Drucker The Deming Cycle: Act Plan Check Do 10/6/2014 3

  4. The Challenges (1 of 2) • Studies by the Standish Group • 2001 data • 44% of software projects finish on time • 56% of projects completed at – • 222% of the duration originally planned • 189% of the original budgeted cost • 70% of projects reduced their planned scope significantly • 30% were cancelled before completion • Ref: http://www.pqa.net/ProdServices/ccpm/W05002001.html

  5. The Challenges (2 of 2) • Capers Jones, Software Productivity Research LLC • 1995 - 2004 data • An analysis of ~250 large software projects • Size > 10,000 function points (~ 1,250,000 statements in C) • Success vs. failure were analyzed at opposite ends of the spectrum • ~ 25 (10%) projects were successful • ~ 50 (20%) projects had delays or overruns below 35% • ~ 175 (70%) projects experienced major delays, budget overruns, reduced scope, or were terminated

  6. Root Cause for Development Schedule Slip • Poor requirements 27% • Unanticipated technical difficulties 25% • Training 20% • Poor Project Management 17% • Lack of management support 6% • Other 5% Source: John Carter - Product Development Consulting, Inc - Spin 1997-

  7. The Current State of the Requirements Phase Engineers’ Awareness at the Start of a Project OthersBest • Priority Decision Criteria 20% 36% • Product Positioning 22% 41% • Strategic Alignment 18% 41 % • Organization Support 20% 43% • Risk Assessment 26% 44% • Competitive Analysis 21% 47% • Understanding User Needs 21% 48% • Regulation Compliance 60% 73% Source: John Carter - Product Development Consulting, Inc Berkeley Software Forum - 1996

  8. Capers Jones • The two most common causes of software project failures are : • Risk analysis • Vague a/o changing customer’s requirements • Ref: http://www.isixsigma.com/library/content/c010618b.asp

  9. The Cost of FixesResources’ bleeding

  10. Log (Cost to Find&Fix per Defect) ($) Cost of QualityIBM -- late 70’s 100K 10K 1K 100 10 0 Reqs. Design Coding Sys.Test Release Phase

  11. Cost to Fix a DefectSemantech -- 90’s SEMATECH Technology Transfer #92111389A-TRG, March 5, 1993 Source: Chuck Hoffman - Virtual Consulting Inc. - Spin 2001

  12. Cost of Quality Log [Cost to Find&Fix per Defect] ($) Log[Cost of NOT Finding & Fixing a req. defect ($/Defect) When faults migrate from phase to phase, they multiply 10-12 times => The most expensive faults are seeded during the Requirements Phase. 100K 10K IBM 1K 100 10 A Quality Gates 0 Reqs. Design Code Sys.Test Release Phase Found 10/6/2014 13

  13. Defects Classified by Time of Introduction (1970s) Jones* Thayer** Boehm*** Bell Labs Requirements 10% 8-10% 15% Functional Design 15% 55% 15-20% Logical Design 20% 25-35% Coding 30% 35% 25% 35% Documentation, etc. 35% 17-20% 45% * “Measuring Programming Quality and Productivity,” Jones, IBM Systems Journal, 1978 ** Software Reliability: A Study of Large Project Reality, Thayer, Lipow & Nelson, North-Holland, 1978 *** “Developing Small Scale Application Software Projects: Some Experimental Results,” Boehm, Proceedings, IFIP 8th World Computer Congress,1980 Source: Chuck Hoffman - Spin 2001

  14. Hewlett Packard’s Experience (1990s) Specification Other Coding Design Source: “Implementing and Sustaining a Software Inspection Program in an R&D Environment,” MacLeod, Hewlett-Packard Journal, June 1993 Source: Chuck Hoffman - Spin 2001

  15. Why Manage Requirements (2000) Distribution of Defects Distribution of Effort to Fix Defects Code 7% Code 1% Other 4% Design 13% Requirements 56% Other 10% Requirements 82% Design 27% Source: Larry Boldt - Technology Builders, Inc. - Spin 2001

  16. Find & Fix Defects as Early as Possible Log Cost to Find & Fix per Defect ($) % of Defects Introduced O Quality Gates 100K 50% 40% 10K 30% 1K O 100 20% 10 10% O O 0 Req. Design Code Sys. Test Release Phase

  17. A New Definition of Quality

  18. Product Quality – Definition 1980  Exceeding Customer expectations Prof. Yoji Akao -- U. of Tokyo Deals withthe total customer experience Part of “Hoshin Kanri” (Japan) Ref – http://www.qfdi.org/

  19. QFD Maps “What” to “How” L=1 M=3 H=5 I M P O R T A N C E FEATURES C O M P E T I T O R T O T A L DEV. HOW MRKT. A B C D E F 1 H H L M 2 N E E D S M L H W H A T 3 L M H 4 H L H 5 M M H 6 L M L H TOTAL 10/6/2014 22

  20. L=1, “Bells & Whistles” M=3 H=7, “A Show Stopper” QFD for this Lecture HOW I M P O R T A N C E C O M P E T I T O R T O T A L DEV. Provide Data Examples Font size Research Sections Colors MRKT. Promote QA/Req. H H M M 91 Correct (no errors) H H M M 91 W H A T Clear/Easy M L H H H H H 108 Low cost M 0 Long shelf life M M L L M 24 Fun/Aesthetic M H L L 39 TOTAL 11066 66423930 353 10/6/2014 23

  21. A Sample of Customers’ Needs (QFD – first column) (1 of 2) • Feature set/Capabilities • Reliability (MTBF) • Safety/Security • Recoverability (zero loss of data) • Scalability (different platforms, apps., tunable, modular)

  22. A Sample of Customers’ Needs (QFD – first column) (2 of 2) • Performance (higher speed) • Usability (easy to set-up, use, maintain) • Friendliness (easy to learn) • Supportability (service, 24x365) • Release date/Availability • Aesthetics

  23. QFD – Benefits – (1 of 2) • A TEAM communication tool • A “semi-mathematical” tool • Drives consensus across organizational • boundaries • Prevents “politics”, “lobbing” and “power • struggle” • Stabilizes requirements

  24. QFD – Benefits – (2 of 2) • Helps organizations to focus on customers’ • satisfaction  Maps customers’ needs into high level features • Cost saving –“Gets it right the first time” • Reduces risk  Identifies competitive features and strategies

  25. QFD – Cost • Planning • Depends on project size, 4-10 marketing and development engineers (all groups involved) • About 1 hr/10X10 matrix • Analyzing, storing, and reporting results

  26. Companies that are using QFD IBM Mitsubishi Digital Toyota AT&T Ford HP GM Sony Daimler Chrysler GE Boeing Raytheon Lockheed Martin Sybase - Clustering Micro Focus - Year 2000 Solution

  27. Entry Criteria for the Requirements Phase • There is – • A vision and an idea • A sponsor for the first phase of the project

  28. Requirements Phase Deliverables • Market Requirements Document • Product Specifications • High Level Project Plan • Management support for the next phase • Process Documents and Infrastructure • Maintenance Documents and Infrastructure • Black Box and Acceptance Test Plans • Initial contracts with potential customersand vendors

  29. Exit Criteria for the Requirements Phase • All documents – • Are written, inspected and approved by all stakeholders • All related issues/risks are resolved or managed • Objectives are measurable, optimized, prioritized and approved

  30. Quality Gates – following the Requirements/Design Phases Documents’ Inspections/Peer Reviews • 1976 – Introduced by M. E. Fagan - IBM • A formal process • Bell Labs experience: • Cost of inspecting all deliverables5-20% of • project development cost* • ROI of inspecting all deliverables 200-1200%* • * Bell Labs data 10/6/2014 33

  31. HP – Inspection Data Grady, R. B. and Van Slack, T., “Key Lessons in Achieving Widespread Inspection Use”, IEEE Software, V. 11, N. 4, Month, 1994, pp. 46-57 10/6/2014 34

  32. The Incremental Model – Web Requirements  H.L.Design L.L.Design L.L.Design L.L.Design Coding Coding Coding Testing Testing Testing Testing Testing Testing Integration Integration Integration Sys.Test Sys.Test Sys.Test Delivery Delivery Delivery

  33. The Incremental Model – Med. Device Requirements  H.L.Design L.L.Design L.L.Design L.L.Design Coding Coding Coding Testing Testing Testing Testing Testing Testing Integration Integration Integration Sub-Sys.Test Sub-Sys.Test Sub-Sys.Test Integration+Test A “big-bang” delivery Delivery

  34. The Iterative Model – Web Reqs+Arch Reqs+Arch. Reqs+Arch. Design Design Design Coding Coding Coding Testing Testing Testing Testing Testing Testing Integration Integration Integration Sys.Test Sys.Test Sys.Test Delivery Delivery Delivery

  35. The Requirements Phase – Lessons Learnt • It is a strategic phase • If this phase is not performed well  the project has a higher probability for failure • Invest about 15-20% of resources • Many organizations skip the phase or implement it poorly • More than 15-20% change in requirements  means a new project and a new round of planning (!)

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