Software Development Process Models

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Software Development Process Models
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The Waterfall Development Model
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The Prototyping Approach
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The Spiral Model
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Iterative Development Process Model
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The Object-Oriented Development Process

• An eight step process (according to Branson and
  Herness) is divided into three phases
• The Analysis Phase
• The Design Phase
• The Implementation Phase

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The Eight Steps of OO Development

• Model the essential system
• Derive candidate-essential classes
• Constrain the essential model
• Derive additional classes
• Synthesize classes
• Define interfaces
• Complete the design
• Implement the solution

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Reviews Included in the Eight Step Process

• Requirements review
• External structure and design review
• Class analysis and verification review
• Class externals review
• Code inspection

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Agile Development Extreme Programming (XP) by
Beck

• The Planning Game
• System Metaphor
• Simple Design
• Pair Programming
• Unit Testing and Acceptance Testing
• Refactoring
• Collective Code Ownership
• Continuous Integration

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Agile Development Extreme Programming (XP)
(Contd)

• On-site Customer
• 40-Hour Week
• Small Releases
• Coding Standard

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The Cleanroom Methodology
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The Defect Prevention Process
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Process Maturity Frameworks and Quality Standards

• The SEI Process Capability Maturity Model
• The SPR Assessment
• The Malcolm Baldrige Assessment
• ISO 9000

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The SEI Process Capability Maturity Model (CMM)

• CMM includes five levels of process maturity
• Initial Chaotic
• Repeatable Informal methods/procedures
• Defined Qualitative control of cost/schedule
• Managed Statistical control of quality
• Optimizing Quantitative basis for process
  improvement

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The SEI Process Capability Maturity Model (Contd)

• The assessment methodology depends on a
  questionnaire.
• The pervasive use of software metrics and models
  is a key characteristic of level 4.
• The following metrics related topics are
  addressed by the questionnaire
• Profiles of software size maintained for each
  software configuration item over time
• Statistics on software design errors

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The SEI Process Capability Maturity Model (Contd)

• Topics are addressed by the questionnaire
  (contd)
• Statistics on software code and test errors
• Projection of design errors and comparison
  between projected and actual numbers
• Projection of test errors and comparison between
  projected and actual numbers
• Measurement of design review coverage
• Measurement of test coverage

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The SEI Process Capability Maturity Model (Contd)

• Topics are addressed by the questionnaire
  (contd)
• Tracking of design review actions to closure
• Tracking of testing defects to closure
• Database for process metrics data across all
  projects
• Analysis of review data gathered during design
  reviews

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The SEI Process Capability Maturity Model (Contd)

• Topics are addressed by the questionnaire
  (contd)
• Analysis of data already gathered to determine
  the likely distribution and characteristics of
  the errors in the remainder of the project
• Analysis of errors to determine their
  process-related causes
• Analysis of review efficiency for each project

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The Capability Maturity Model Integration (CMMI)

• The integration of CMMs for
• Software engineering
• Systems engineering
• Integrated product and process development
• Acquisition

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The Capability Maturity Model Integration (Contd)

• The five CMMI levels are
• Initial Ad hoc and chaotic
• Managed Focuses on basic project management
• Defined Focuses on process standardization
• Quantitatively Managed Focuses on quantitative
  management
• Optimizing Focuses on continuous process
  improvement

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The SPR Assessment

• Developed by Software Productivity Research, Inc.
• SEI focuses on software organizational structure
  and software process.
• SPR focuses on strategic corporate issues and
  tactical project issues that affect quality,
  productivity, and user satisfaction.

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The SPR Assessment (Contd)

• SPR questions regarding software quality and
  metrics relate to
• Quality and productivity measures
• Pretest defect removal experience among
  programmers
• Testing defect removal experience among
  programmers
• Project quality and reliability targets
• Pretest defect removal at the project level
• Project testing defect removal
• Postrelease defect removal

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The Malcolm Baldrige Assessment

• The most prestigious quality award in the United
  States
• Evaluation criteria cover
• Leadership
• Information and analysis
• Strategic quality planning
• Human resource utilization
• Quality assurance of products and services
• Quality results
• Customer satisfaction

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ISO 9000

• A set of standards and guidelines for a quality
  assurance management system
• ISO 9000-3 covers software development
• Twenty elements are evaluated
• Management responsibility
• Quality system
• Contract review
• Design control

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ISO 9000 (Contd)

• Twenty elements (contd)
• Document control
• Purchasing
• Purchaser-supplier product
• Product identification and traceability
• Process control
• Inspection and testing
• Inspection, measuring, and test equipment
• Inspection and test status

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ISO 9000 (Contd)

• Twenty elements (contd)
• Control of nonconforming product
• Corrective action
• Handling, storage, packaging, and delivery
• Quality records
• Internal quality audits
• Training
• Servicing
• Statistical techniques

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ISO 9000 Software Metrics Requirements

• Product Metrics Measurements should be used for
  the following purposes
• To collect data and report metric values on a
  regular basis
• To identify the current level of performance on
  each metric
• To take remedial action if metric levels grow
  worse or exceed established target levels
• To establish specific improvement goals in terns
  if metrics

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ISO 9000 Software Metrics Requirements (Contd)

• At a minimum, some metrics should be used that
  represent
• Reported field failures
• Defects from customer viewpoint

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ISO 9000 Software Metrics Requirements (Contd)

• Process Metrics
• Ask if in-process quality objectives are being
  met
• Address how well development process is being
  carried out with check-points
• And how effective the development process is at
  reducing the probability that faults are
  introduced or go undetected

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Differences Between MBNQA and ISO 9000

• MBNQA is focused on quality results and customer
  satisfaction.
• ISO 9000 is focused on a quality management
  system and process control say what you do, do
  what you say, and prove it