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Requirements: Elicitation

Requirements: Elicitation

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Requirements: Elicitation

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  1. EMIS 8390 Systems Engineering Tool—applying tools to engineering systems Requirements: Elicitation UPDATED 9/02/04 Mark E. Sampson

  2. Requirements Elicitation • Standish Group claims “lack of user input” is one of the main contributors to runaway projects. • Some quotes: • “15% of projects fail outright, 51% are challenged” Standish • “53% of projects will cost 189% of estimates”Standish • “only 67% of originally defined features show up in the finished product, of those 45% are NEVER used” Standish • “half of resources spent on product development are spent on products that fail” 2003 Harvard Business School Cyberposium • “90% of electronics components function as designed, 50% of them fail when integrated with their systems” IEEE Design Magazine …the process of discovering the requirements for a system by communication with customers, users, and other stakeholders. [Sommerville, 1997]

  3. Requirements Elicitation Problems…”Yes, but” • “Yes, but…” • …that’s so cool, but it would be nice if it… • Caused by human nature • Anticipate some “buts…” • Do them early in the process with prototypes • Tend to be at the interfaces/touch points [Leffingwell, 2000]

  4. Requirements Elicitation Problems…”Gold Miner” • “When are you rich enough” • …let’s do another pass by… • …there’s a few more avenues we haven’t checked… • Systems Engineering nature • Scope statement boundaries the problem and establishes your objectives (how you know when you’ve arrived). When the extracted requirements adequately address your objectives…your there. [Leffingwell, 2000]

  5. Requirements Elicitation Problems…”bring me a rock” • Users don’t know what they want • Prototyping • Stick with it until you get some definition • Watch them in action (beware the Hawthorne effect) [Leffingwell, 2000]

  6. Requirements Elicitation Techniques…Reuse • Find if it’s already been done and reuse it. • Saves money & time • Reduces risk • How? • TRIZ uses inventive patterns (see class 1) • Analogs…Nature (already worked out the kinks)

  7. Brain (Project Management) Nervous System (SE & SE Tools--connects management to project) Muscular System (Does the work… engineering, etc.) Epidermal System (facilities, security) Digestive System (Personnel, finance provides energy/resources for project) Circulatory System (Information Systems, LAN’s, PDM) Skeletal System (project support groups) Respiratory System (Marketing bringing in new ideas) Analog: Anatomy of a project...

  8. Requirements Elicitation Techniques…Interviews • Find a user/customer and ask them. • Proves there is a need. • Boundaries the market • Live communication, builds relationship with market • How? • Unbiased questions…”who is the user”? • Ask Why? Solutions Selling.

  9. Requirements Elicitation Techniques…Brainstorming • Find a user/customer and brainstorm around a problem (see class 1). • Idea generation and reduction • Combine ideas • Voting schemes • How? • Live, using stickee note • Web-based brainstorming • A variety of techniques supported by tools--Delphi, mindmaps,…both installed and web-based

  10. Requirements Elicitation Techniques…Surveys • Find a potential user and get them to answer some survey questions. • more efficient to cover a wide swath of potential users • Statistically measurable/confidence • How? • Paper • Web-based Surveys—TcCommunity, grapevine, formsite, web-online-surveys,… • How to write questions to get to the information you need? http://www.statpac.com/surveys/

  11. Requirements Elicitation Techniques…Use Cases • User interaction model • Identify who, what & how of product behavior • Describe the interaction between user and system—what the system does for the user • Describe functional behavior • How? • Modeling environments that support UML • Drawing/diagramming tools (Visio, PPT)

  12. Requirements Elicitation Techniques…Regulations/Standards • Describe what the product must comply with… • …another source of requirements • …constraints/drivers point out things you can do nothing about… • Where do you get themfrom? • Introduction/demonstration • With George Bell/Steve HaasInformation Handling Services

  13. TCT Kill Chain Engaged by a Joint Battle Force J-STARS w ATR U-2 UAV TADIL NET DCGS XXX ARMY Tactical Operations Center CAOC XX XX BCC USMC TAOC XX AIR DEFENSE TOC AEGIS • Requirements Elicitation Techniques…Scenario Generators • Virtual environments describing aspects that impact our system • Weather/environment • Economic/Financial (ALM, ESG,…) • Missions (TAC Brawler), Electronics (EWSG) • …produces an eventchain/time line that can drive out requirements (…must deal with 3 targets at the same time)

  14. Requirements Elicitation Techniques…Data Mining • Similar to reuse, except it relies on prior data to drive out requirements. The problem is finding the needle in the haystack… • …for example: Beer and Diaper Sales spike ~8:00pm • start with existing data and look for anomalies/patterns • Tools…Probe, KD1, PVWave,… • Data Analysis Introduction & • Demonstration with Hiedi Hager • Visual Numerics

  15. Requirements Elicitation Techniques…other • Role playing • Storyboarding • Prototyping • JAD (Joint Application Development) • Delphi • Gaming • …