1 Lecture 1.4: Life Cycle Models Dr. John MacCarthy UMBC CMSC 615 Fall, 2006

2 Agenda What is a Life Cycle and Life Cycle Model? What is a Development Process/Life Cycle Model? Code and Fix Development Process Classic Waterfall Life Cycle Model General Life Cycle Milestones and SE Products Improved Waterfall Life Cycle Models Concurrent Waterfall Life Cycle Models Other Modified Waterfall Life Cycle Models “V” Model* Spiral Life Cycle Models Iterative Development Life Cycle Model (RUP) Block Development Life Cycle Models DOD Acquisition Life Cycle Model (Global)* Conclusions * This course will focus on these life cycle models (since these are the ones that are addressed explicitly in DoD Acquisition Documentation)

3 What is a Life Cycle? Life Cycle: Describes how a product goes from from conception to retirement Life Cycle Model (LCM): Generally a set of phases (with exit/entry milestones) that describe how a product goes from conception to retirement. Each phase of a Life Cycle is generally characterized by a set of: Activities Milestones Artifacts Reviews Examples: Classic Waterfall LCM (1970) Improved Waterfall LCM (1981) “V” LCM (1991) Spiral Deployment LCM (1981) Iterative Development LCM (1999) Block/Incremental Development LCM DoD Acquisition LCM Note: This course will focus on the “V” Model, which is a variant of the simple Waterfall model

4 What is a Development Life Cycle/Process? Generally it is the portion of the life cycle dealing with development. Generally a (Software) Development Life Cycle/Process includes: Requirements Design Implementation/Coding/Unit Testing Integration Testing/Verification Notice that it generally excludes: Manufacturing Deployment Operations Retirement

5 Classic Waterfall Model (Royce 1970) Requirements Analysis Specifications Design Implementation Testing Maintenance SRR/SDR/SFR - Concept of Operations - System Specification - Conceptual Design - Architecture Artifacts PDR - Prime Item Specification - Preliminary Design - Architecture Artifacts CDR - Design Document (Detailed Item Spec) TRR - Prototype (1 st Unit) Product - TEMP FCA/SVR - Prototype (1 st Unit) Product PRR/PAR PCA

6 Technical Reviews and Audits (Ch 11) Alternative Systems/Concept Review (ASR/ACR) Select preferred system concept Approve/Kick off acquisition System Requirements Review (SRR) Approve/Kick off start of project PMP/SEMP/TEMP Customer Requirements Top-Level Functional Architecture Top-Level Conceptual Design Draft Specs System Design/ Definition/ Functional Review (SDR/SFR) Approve System Spec Approve Conceptual Design End of Concept/Architecture Phase Software Specification Review (SSR): See PDR Preliminary Design Review (PDR) Approve Performance Item Spec Approve Preliminary Design End of Requirements Phase Critical Design Review (CDR) Approve Final Design (DI Specs) End of Design Phase Test Readiness Review (TRR) Approve start of [integration] testing End of Development Phase Functional Configuration Audit/ System Verification Review (FCA/SVR) [1 st unit acceptance] Verifies that PI Spec meets Customer Requirements Verifies that DI Spec meets PI Spec End of Testing Production Readiness/Approval Review (PRR/PAR) Approve start of unit production Physical Configuration Audit (PCA) Formalizes (corrected) Product Baseline for Production Follows PRR/PAR Note: Names depend on what standard one is using (MS-1521B, DODI , EIA/IS-632, IEEE P1220).

7 Improved Waterfall Model (Boehm 1981) (Sage, Rouse 1999)

8 Concurrent Waterfall Requirements Analysis Specifications Development Design Implementation Testing (Manufacturing,) Deployment, Operations, & Retirement SRR/SDR/SFR PDR FCA/SVR CDR TRR Note: This is an approach that is being used by many programs today to accelerate development. To some extent, both the Iterative and Spiral Models are a form of this.

9 Modified Waterfall Life Cycle Models Waterfall with Concurrent Design/Development Evolutionary Prototyping Staged Delivery/Design to Schedule Evolutionary Delivery Note: See “Rapid Development” (1996) by Steve McConnell, Chapter 7

10 “V” Model from SEF ( Ould, 1990)

11 DoD SDD Phase “V” Model

12 Spiral Model (Boehm, 1981) (Sage, Rouse 1999)

13 Iterative Life Cycle Model (Kruchten 1999)

14 Block Development Life Cycle Models: Evolutionary/ Incremental Deployment and Spiral Development Block 1 Development Block 1 Operations Block 1 Retirement Block 2 Development Block 2 Operations Block 2 Retirement Block 3 Development Block 3 Operations Block 3 Retirement Each Block/Increment provides a major evolutionary increase in, or increment of, system capability Block 4 Development Block 4 Operations Block 4 Retirement Spiral 1-N Generally the “Generic Spiral Process” is tailored to the project.

15 DoD Acquisition Process Life Cycle DoD Instruction (2003)

16 Conclusions Only the Improved Waterfall Model and the DoD Acquisition Life Cycle Model are true “Life Cycle Models” the others are really “Development Models” (Why?) This course will focus on the “V” Development (Life Cycle) Model and the DoD Acquisition Life Cycle Model Most Development Models are derived from the Classic Waterfall Model The activities, products, reviews and milestones associated with the Classic Waterfall model generally apply to the other Development Models

17 “V” Model (Ould, 1990) (Sage, Rouse 1999)