ITSE == Introduction To Software Engineering

NCTUCS 2013-Fall Introduction to Software Engineering by Professor Feng-Jian Wang

Ch2 - Process Models

Process Patterns

• A process pattern
  • describes a process-related problem that is encountered during software engineering work
  • identifies the environment in which the problem has been encountered
  • suggests one or more proven solutions to the problem.
• A process pattern provides you with a template - a consistent method for describing problem solutions within the context of the software process.
• Patterns can be defined at any level of abstraction. In some cases, a pattern might be used to describe a problem (and solution) associated with a complete process model.
• patterns can be used to describe a problem (and solution) associated with a framework activity (e.g., planning) or an action within a framework activity (e.g., project estimating).
• Ambler [Amb98] has proposed a template for describing a process pattern:
  • Pattern Name
  • Forces - The environment in which the pattern is encountered and the issues that make the problem visible and may affect its solution.
  • Type
    • Stage pattern - defines a problem associated with a framework activity for the process.
    • Task pattern - defines a problem associated with a software engineering action or work task and relevant to successful software engineering practice.
    • Phase pattern - define the sequence of framework activities that occurs within the process, even when the overall flow of activities is iterative in nature.
  • Initial context - Describes the conditions under which the pattern applies.
    1. What organizational or team-related activities have already occurred?
    2. What is the entry state for the process?
    3. What software engineering information or project information already exists?
  • Problem - The specific problem to be solved by the pattern
  • Solution - Describes how to implement the pattern successfully
  • Resulting Context - Describes the conditions that will result once the pattern has been successfully implemented.
  • Related Patterns - Provide a list of all process patterns that are directly related to this one.
  • Known Uses and Examples - Indicate the specific instances in which the pattern is applicable.

Prescriptive Process Models

The Waterfall Model

The V-Model

Incremental Process Models

Evolutionary Process Models

Evolutionary models are iterative.
They are characterized in a manner that enables you to develop increasingly more complete versions of the software.

• Prototyping
  

• The Spiral Model
  

• Concurrent Models
  

The Unified Process (UP)

• UP Phases
• UP Work Products
• Personal Software Process (PSP)
• Team Software Process (TSP)