Software Quality Management

1
Software Quality Management

• Objective of quality management is to achieve the
  level of product and service quality as defined
  by the organization (beat it if possible).
• Participate in the definition of organizational
  quality goals
• Define the standards and procedures to be used
  for software development and support
• Monitoring and checking that the standards and
  procedures are followed
• Project and anticipate product and service
  quality and recommend actions if necessary

items are the places where quality management
earns its real value as opposed to just quality
assurance.
2
Key Components of Quality Management
Set Organizational Quality Goals
Quality Goals
Inputs from all parts of the Organization
Quality Assurance
The establishment of standards and procedures for
the organization
Measuring and Projecting to see if
organizational goals are met
Quality Planning
Selection of the appropriate set of standards and
procedures, with project manager.
Quality Control
Monitoring and ensuring that the
selected standards and procedures are followed
3
Quality Assurance

• Defines a framework for achieving the quality
  goals via defining a set of organizational
  standards and procedures
• Product Standards and Procedures
• manuals, brochures and user guides (online or
  printed)
• display screen interfaces
• on-line messages and help material
• programs and data
• etc.
• Process Standards and Procedures
• description of the software activities
• description of forms to be used with the
  activities
• descriptions of the measurements and how to use
  them
• etc.

4
Quality Assurance (cont.)

• There are several standards and procedures
  defined by organizations such as IEEE, ANSI, etc.
  that one may want to use as references instead of
  generating from scratch.
• Involve people from other organizations in both
  the picking and generation of standards/procedures
  .
• Review the the ones chosen and get organizational
  support and commitment
• Provide tools and support for the standards and
  procedures
• Product and Process quality are not the same
• assumed that improving process quality improves
  product quality
• process based quality management, when applied
  alone, has a tendency of becoming beauracratic
  so it must be constantly analyzed

5
Quality Planning

• Quality plan should select those standards and
  procedures that are fit for the specific
  organization or project to which they are applied
• Quality plan should include the following
• Critical quality goals for this project (this is
  very difficult)
• measurable
• attainable
• Critical non-quality goals such as schedule,
  cost, scalability that may affect quality
• Risk items that may affect the quality goal
  attainment
• Process that will be used for development and
  support
• The standards and procedures that will be used to
  support the chosen process

6
Some Quality Attributes

• Quality goals are often expressed in terms of one
  or more of the following attributes
• Reliability in terms of software failures
• Availability in terms of amount of time that
  the software is operational
• Usability no simple measurement
• Maintainability no simple measurement
• Complexity multiple measurements exit
• Learnability no simple measurement
• etc.
• An attribute that is difficult to measure makes
  it a very soft target to achieve.

7
Quality Control

• Quality control, as process management, is often
  viewed as beauracratic because it oversees how
  and if all the processes and standards are being
  followed
• Review of the process and the activities as
  development marches through the procedures and
  standards.
• Use some automated tool to analyze (compare)
  against the standards that apply to the
  particular project
• Assess the various defects that are discovered in
  the artifacts (through reviews or tests) that are
  produced at each stage of development and
  recommending what actions that need to be taken
  (this is a much more difficult task and requires
  more resource)

8
Software Metrics

• In order to set quality goals and gauge if the
  goals have been attained, the goals must be
  measurable, for both product and process
• Control metric
• usually measures the process quality
• e.g. review and inspection people hours
• Predictor metric
• usually measures the product quality
• e.g. number of failures during test or module
  complexity
• There is a high degree of reluctance to introduce
  measurements into an organization
• lack of expertise
• lack of process definition

9
Software Attributes and Measurability Realtionship
Cyclomatic complexity
Reliability
Average fan-in and fan-out
Program size in loc
Maintainability
Pages of user manual
Usability
Coupling in terms of parameters passed
External Quality Attributes
Internal Measurable Attributes
10
Software Metrics

• For an software attribute to be useful as a
  control or predictor they must satisfy at least
  three conditions
• The (internal) attribute must be measured
  accurately
• There must be a strong relationship between what
  can be measured (internal attribute) and the
  external desirable quality
• This relationship between the internal attribute
  and the external quality attribute is clearly
  understood and validated

11
Metric and Quality Goal

• Coming up with Quality Goals and Objectives is a
  difficult task
• Quality attributes need to be identified and
  prioritized
• e.g. for users usability, understandability,
  reliability, modifiability, localization, etc.
• e.g. for developers reliability, modifiability,
  etc.
• Measurable attributes need to be identified and
  related to the quality attributes
• static measure size, complexity, number of
  classes, etc.
• dynamic measure number of failures, response
  time, etc.
• Measurement Effort
• resource cost
• skills or training
• time

12
Quality Assessment and Projection

• We can assess and project quality or any specific
  attribute only if the following are true
• Measurable Goals and Objectives are set
• Measurements are taken
• Relationship between objectives and the
  measurements are understood and validated
• Assessment and Projection scheme is valid