Transcript Ch02
Software Engineering: A Practitioner’s Approach, 6/e Chapter 2 Process: A Generic View copyright © 1996, 2001, 2005 R.S. Pressman & Associates, Inc. For University Use Only May be reproduced ONLY for student use at the university level when used in conjunction with Software Engineering: A Practitioner's Approach. Any other reproduction or use is expressly prohibited. Coming up: A Layered Technology 1 A Layered Technology Software Engineering tools methods process model a “quality” focus Coming up: What is a process framework 2 What is a process framework Process framework Framework activities work tasks work products milestones & deliverables QA checkpoints Umbrella Activities Coming up: Framework Activities 3 Framework Activities Communication Planning Modeling Construction Analysis of requirements Design Code generation Testing Deployment What are some artifacts (work tasks, work products, milestones & deliverables, QA checkpoints) of each activity? Coming up: Umbrella Activities 4 Umbrella Activities Coming up: The Process Model: Adaptability Software project management Formal technical reviews Software quality assurance Software configuration management Work product preparation and production Reusability management Measurement Risk management 5 The Process Model: Adaptability The framework activities will always be applied on every project ... BUT The tasks (and degree of rigor) for each activity will vary based on: Coming up: Text Question the type of project characteristics of the project common sense judgment; concurrence of the project team 6 Question Pick any one of the project types below and tell me which process activity would be emphasized or deemphasized and why Project Types: - 1.Space Shuttle control system - 2.Web-based calendar - 3.Embedded controller in your refrigerator - 4.Automatic “daily fortune” text-messager Framework Activities Communication Planning Modeling Construction Coming up: The CMMI Analysis of requirements Design Code generation Testing Deployment 7 The CMMI The CMMI defines each process area in terms of “specific goals” and the “specific practices” required to achieve these goals. Specific goals establish the characteristics that must exist if the activities implied by a process area are to be effective. Specific practices refine a goal into a set of processrelated activities. PP - project planning REQM - Requirements Mgmt MA - Measurement and Analysis CM - Configuration Mgmt PPQA - Process and Product QA Coming up: The CMMI 8 The CMMI Level 0 - Incomplete - process area is either not performed or does not achieve all specified goals. Level 1 - Performed - All specific CMMI defined goals of the process area have been satisfied Level 2 - Managed - All work conforms to an organizationally defined policy; all people doing the work have access to adequate resources to get the job done; work tasks are monitored, controlled and reviewed, evaluated for adherence to the process description Level 3 - Defined - process is tailored according to organization’s tailoring guidelines. Work products, measurements, etc… are contributed to the organizational process assets Level 4 - Quantitatively managed - Process area uses quantitative measurement to control and improve the process area. Quantitative objectives for quality and performance are established and used. Level 5 - Optimized - Process area adapted and optimized to meet changing customer’s needs and continually improve the process area Coming up: Process Assessment 9 Process Assessment The process should be assessed to ensure that it meets a set of basic process criteria that have been shown to be essential for successful software engineering. Many different assessment options are available: SCAMPI --- assessed for CMMI standards compliance SPICE --- assessed for ISO/IEC15504 compliance ISO 9001:2000 --- assessed for ISO 9001 compliance Process Assessment is often used to “certify” a company as compliant (“Company X is ISO9001 certified “or “Company Y is CMM level 4”) Coming up: Assessment and Improvement 10 The Waterfall Model Do all process steps in the following order (this is generally thought of as the most basic model) Com m unic a t ion proje c t init ia t ion re quire m e nt ga t he ring Coming up: Different families of models Planning estimat ing scheduling tracking Mode ling analysis design Const r uc t ion code t est De ploy m e nt de liv e ry s upport f e e dba c k 17 Different families of models Prescriptive (ch 3) Agile (ch 4) Prescriptive Models 1970->Present Agile Models 2001->Present -Waterfall (1970) -Evolutionary (1975) -Incremental (1975) -Spiral (1988) -RAD (1991) - eXtreme Programming (1999) - SCRUM (1990s) - DSDM (1997) - Crystal (2001) All dates are approximate based on publications Coming up: Different families of models 18 Different families of models Prescriptive (ch 3) Agile (ch 4) Goal: Higher Quality Software Goal: Higher Quality Software Philosophy: Philosophy: •Bring order to chaos •Provide repeatability/consistency •Provide ability to control •Provide ability to coordinate teams •Individuals and interaction over process and tools •Working software over large documentation •Customer collaboriation over contract negotiation •Responding to change over following a plan Which is probably better for large teams? A. Prescriptive B. Agile C. Same Which is probably better for a web application? Which is probably better for Mars rover control system? Which is produces better software? End of presentation 19