22 September 2010

Fundamental Steps STEPS  Requirements  Design  Implementation  Integration  Test  Deployment  Maintenance MODELS Waterfall Spiral Iterative DIFFERENCES How often Overhead

Historical Perspective  Waterfall: 1970, built on 1950’s stage- wise processes Recognized need for feedback  Iterative (agile): late 70s,modeled on evolutionary model Didn’t work well for large products  Spiral: 1988, risk-based

Unified Process  Variant of Spiral  Identifies that iterations differ  Also known as Rational Unified Process (Rational products) Rational Unified Process

Personas and User StoriesTypes and Use CasesRequirements

User Requirements - Persona  Microsoft Microsoft  Persona Power Persona Power

Persona excerpt (hotel reservation)

Sources of requirements  People Stakeholders ○ Who are the stakeholders? Issues: ○ Conflicting requirements ○ Wants vs. needs Helping the customer articulate the requirements ○ Use cases  Hardware constraints Laws of physics and nature  Social responsibility

Social responsibility  Privacy  Security  How it will (can) be used Does it have the potential for misuse? Can it be used to harm people?

Sources of Requirements: People vs. Other (Brackett, CMU) % of requirements gathered from people Type of application highly constrained unconstrained missile guidance system flight control system for airliner enhancement to corporate accounting system manufacturing control system corporate accounting system video game decision support system for military tactics relatively lowrelatively high