Software Quality Assurance: A survey of an Emerging view

1
Software Quality Assurance A survey of an
Emerging view

• 
  Patricia W.Hurst

2
Issues

• Historical perspective and rationale for Quality
  assurance
• Initiatives to improve software Quality
• Emerging view of Quality assurance
• Presents an organizational structure to support
  Quality assurance methods

3
Background

• Views
• 1960s Functional Era
• what functions should the S/w perform
• 1970s - Schedule Era
• Planning and controlling of S/w projects
• -Introduction of Life Cycle models
• 1980s - Cost Era
• Cost Estimation Techniques
• 1990s Quality Era
• - Increased Society dependence on S/w projects
• - Competition

4
Rationale

• In earlier stages,the Quality of the S/w product
  was assessed on the basis of Back-end Testing.
• The above approach is no longer applicable .The
  reasons for wanting to improve S/w processes and
  Quality
• gt Moral Obligation
• - Increasing reliance on s/w in life
  critical systems
• gt Customer satisfaction
• -Customers have many options
• gt Cost effectiveness
• -H/w cost going down,need efficient
  use of Human S/w resources
• gt Predictability
• -To avoid delays increase in
  project Costs
• gt Application Demand
• gt International Competition

5
Quality Improvement Initiatives

• Shortcomings in managing development and
  maintenance processes were recognized as prime
  inhibitors of growth in S/w productivity and
  quality.
• Several initiatives were proposed to overcome
  these shortcomings
• Software Engineering Institute - CMM
• ISO 9000-3
• BOOTSTRAP
• SPICE

6
SEI Capability Maturity Model

• Fig.1 ,Pg 83
• Recommends practices in a number of key process
  areas that help to enhance the S/w development
  maintenance capability of an Org.
• The CMM model provides a rating scale composed of
  five maturity levels
• Based on the principles of incremental and
  continuous process improvement ( Proposed by
  Walter Shewart others)
• Usage of this model has increased productivity
  and Quality in many Orgs.
• E.g. Raytheon .see Fig 2.Pg 83

7
Quality Improvement Initiatives Contd..

• ISO 9000-3
• - Guidelines for the application of ISO 9001
  to the development,Supply Maintenance of S/w.
  
• Part of standards proposed by ISO
• BOOTSTRAP
• A project by European strategic Programme for
  Research in Information Technology(ESPRIT)
• Applied SEI model to European S/w industry.
• SPICE(S/w Process Improvement Capability
  dEtermination)
• - Sponsored by ISO
• - Objective To develop an International
  standard for S/w process assessment using the
  best features of CMM.
• - HP uses SQPA (S/W Quality and Productivity
  Analysis)

8
Quality Assurance Definition

• IEEE Definition 1.A planned systematic pattern
  of all actions necessary to provide adequate
  confidence that an item or product conforms to
  established technical requirements
• IEEE Definition 2.A set of activities designed
  to evaluate the process by which products are
  developed or manufactured
• CMM Definition of purpose. The purpose of
  quality assurance is to provide management with
  appropriate visibility into the process being
  used by the software project and of the projects
  being built
• IEEE Def 1 is broader in scope while IEEE Def 2
  CMM Def is narrower in scope.
• To bridge the gap between Broad narrow
  definitions,terms such as Quality Program
  Quality management are used.

9
Quality Management Functions

• QM is concerned with Quality-related activities
  across the spectrum of a S/W development
  Organization.
• QM must address quality functions at two levels
• -Organizational Level
• -Project Level
• Fig 3 . Pg 85
• Organizational level functions are those
  necessary to define and support the processes and
  methodologies which will be used by individual
  projects with in the organization
• Project level functions are those necessary to
  carry out the defined processes,using the defined
  methodologies ,for a specific project.

10
Organization level Functions

• Def. Of S/w development processes
• - This function defines and documents the
  processes which development projects will
  follow.Processes include activities,procedures,doc
  umentation, standards required t project level.
• Improvement of S/w Development process
• - This phase requires
• -Evaluating current processes and
  products produced
• -Identifying weak areas
• -Modifying the weak areas.

11
Organization level Functions cont..

• Metrics Collection and Analysis
• - Play an important role in evaluating and
  improving the development processes and the S/w
  products.
• - Implementation is complex.According to
  a survey,two out of three measurement efforts
  failed or discontinued after two years.
• - Successful Metrics implementation -
  Motorola
• -Metrics can be classified into two types
• -Process metrics
• -Used to improve the development
  maintenance processes.
• E.g. defects associated with
  testing
• -Product metrics
• -Used to improve the S/w its
  associated products.
• E.g complexity of the design

12
S/w Metrics Framework

• Fig 4. Pg 86
• Hierarchical Approach Used to define product
  metrics.
• The first level establishes high level Quality
  factors
• The second level identifies the S/w attributes
  which define the factor.
• The third level identifies the metrics which can
  b used to measure the degree of presence of each
  attribute ,and thus the quality factor.
• E.g.
• 
  maintainability
• consistency
  simplicity modularity
• Another model CUPRIMDA used by IBM. Fig 5 pg 87
• FURPS model used by HP

13
Goal/Question/Metrics paradigm

• A useful approach for developing a set of
  metrics.
• Basic principle
• - Each organization has some goals
• - For each goal there is a set of Questions
  that might help whether you are achieving your
  goal.
• - Many of these questions have answers that
  can be measured.
• Metrics Training program
• -METKIT Developed by Esprit

14
Project level Functions

• Project Planning Tracking.
• Product Engineering
• -R . A, design, Implementation and Testing
• Verification Validation
• Requirements Management
• Configuration Management
• Reviews documentation for each phase is
  important for effective Quality.

15
Quality management Organization

• Critical element of success in implementing a
  quality program.
• Fig 7. Pg 90
• Discussion ??????