Chapter 2 The Process 1 Software Engineering Defined

Chapter 2 The Process 1

Software Engineering Defined by IEEE 610. 12 -1990 as: (1) The application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software; that is, the application of engineering to software. (2) The study of approaches in (1). 2

A Layered Technology Software Engineering - provide support for methods tools and processes methods - technical how tos -glue that holds layers process model together a “quality” focus - bedrock 3

Types of Software Maintenance Corrective Adaptive Perfective Preventive 4

A Common Process Framework Common process framework Framework activities Task Sets tasks milestones, deliverables SQA checkpoints Umbrella Activities 5

Umbrella Activities Software project management (tracking and control) Formal technical reviews Software quality assurance Software configuration management Document preparation and production Reusability management Measurement Risk management 6

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: the type of project (an “entry point” to the model) characteristics of the project common sense judgment; concurrence of the project team 7

SEI CMM Levels 8

Process as Problem Solving 9

The Linear Model 10

Waterfall Model Software Reqmts Analysis Software Item 1 System Reqmts System Analysis Architectural Design Software Detailed Design Software Architectural Design Software Integration Software Coding & Testing Software Item n. . . Software Qualification Testing System Integration, Qualification & Release Activities Hardware Items Note: 1) Software Lifecycle Activities are bolded / shaded 2) This model is consistent with IEEE/EIA 12207. 2 - 1997 11

Prototyping 12

RA D 13

The Incremental Model 14

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An Evolutionary (Spiral) Model 16

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Still Other Process Models WINWIN spiral model - defines negotiating activities and adds anchor points to spiral model Concurrent process model—recognizes that different part of the project will be at different places in the process Component-based development model—the process to apply when reuse is a development objective Formal methods—the process to apply when a mathematical specification is to be developed Cleanroom software engineering—emphasizes error detection before testing 18