unit 8

• Process paradigm


  Very general process models that provide the rough structure of software processes without going into detail
• Software process model framework

  Follows the structure specified in the process paradigm and adds detailed descriptions of roles, responsibilities, specific activities, and their dependencies
• Individual software process model

  Describes how a development process should run transparently for all those involved in an organization
• Waterfall model


  1. Requirements

  2. Analysis

  3. Design

  4. Implementation

  5. Test

  6. Operation
• Waterfall model


  • Step-by-step processing of individual phases in a defined sequence
  • Like a waterfall, a software project "falls" one after the other from "top to bottom"
  • Each individual phase is fully completed before moving to the next phase
  • Possibility of feedback between adjacent phases
• Waterfall model (from management perspective)

  • Divides software process into clear phases with defined results
  • Allows clear organizational responsibilities to be defined
  • Allows current status and project progress to be monitored
  • Allows task areas to be clearly structured, especially in distributed projects
  • Demands comprehensive and complete documentation of results
• The definition of a rigid sequence of activities in the waterfall model is the opposite of the knowledge-driven nature of software projects
• The waterfall model prevents the start of successor phases for individual elements that have already been completed
• The waterfall model should only be used as a rough guide when creating software process models for industrial information systems
• 1. model


  1. Requirements analysis

  2. Construction phases

  3. Test phases
• 1. model


  • 1:1 assignment of construction phases (left half of V) and phases to be tested (right half of V)
  • Path through software process is a result of the sequence of the defined phases
  • Each phase of the construction is assigned a specific test level
• Evolutionary/Agile development


  1. Determine functions to be implemented

  2. Implement functions

  3. Integrate new functions into existing system

  4. Test and evaluate current software version
• Evolutionary/Agile development


  • Software process "turns in a circle" around a finished piece of software
  • Software engineering core activities are not carried out and documented in full in one phase, but in smaller parts that interlink in each cycle
  • Considers that many insights into requirements and technological solutions can only be gained during software development
  • Allows new knowledge to be incorporated directly in each new cycle
  • Allows errors and inaccuracies to be quickly identified and eliminated
  • Provides rapid availability of a basically executable system
• Evolutionary/Agile development has no phases with clearly defined results, but all software engineering core activities are repeated in small parts in short cycles
• Evolutionary/Agile development does not create a complete specification at the beginning of the software process, so the specific functional scope of the system is only precisely defined during development
• Agile software development


  • A thought scheme or design principle for software development activities, not specific techniques or processes
  • Ensures that all important decisions are made based on knowledge gained during the project (knowledge-driven)
• Classic software development


  Focuses more on plans that were created in the run-up to the project or in the early project phases (assumption-driven)