Management components of software quality

basic SQA management tools offered here are:

• Project progress control
• Software quality metrics
• Software quality costs

Project progress control

The main components of project progress control are:

• Control of risk management activities
• Project schedule control
• Project resource control
• Project budget control.

Control of risk management activities

This refers to the software development risk items identified in the preproject stage, those listed in contract review and project plan documents, together with other risk items identified throughout the project’s progress

Project schedule control

This deals with the project’s compliance with its approved and contracted timetables. Follow-up is based mainly on milestones, milestones set in contracts, especially dates for delivery of specified software
products to the customer or completion of a development activity, generally receive special emphasis

Project resource control

This focuses on professional human resources but it can deal with other assets as well. For real-time software systems and firmware, software development and testing facilities resources typically demand the most exacting control.

Project budget control

The main budget items demanding control are:

• Human resources
• Development and testing facilities
• Purchase of COTS software
• Purchase of hardware
• Payments to subcontractors

Software quality metrics

Objectives of quality measurement

The metrics are used for comparison of performance data with indicators, quantitative values such as:

• Defined software quality standards
• Quality targets set for organizations or individuals
• Previous year’s quality achievements
• Previous project’s quality achievements
• Average quality levels achieved by other teams applying the same development tools in similar development environments
• Average quality achievements of the organization
• Industry practices for meeting quality requirements.

Classification of software quality metrics

The first classification category distinguishes between life cycle and other phases of the software system:

• Process metrics, related to the software development process
• Product metrics, related to software maintenance

The second classification category refers to the subjects of the measurements:

• Quality
• Timetable
• Effectiveness (of error removal and maintenance services)
• Productivity

A sizeable number of software quality metrics involve one of the two following measures for system size:

• KLOC (thousands of code lines)
• Function points

Process metrics

Software development process metrics can fall into one of the following categories:

• Software process quality metrics
• Software process timetable metrics
• Error removal effectiveness metrics
• Software process productivity metrics.

Product metrics

Process productivity metrics

 Implementation of software quality metrics

• Definition of software quality metrics – relevant and adequate for teams, departments, etc.
• Regular application by unit, etc.
• Statistical analysis of collected metrics data. 

Limitations of software metrics

• Budget constraints in allocating the necessary resources (manpower, funds, etc.) for development of a quality metrics system and its regular application.
• Human factors, especially opposition of employees to evaluation of their activities.
• Uncertainty regarding the data’s validity, rooted in partial and biased reporting.

Costs of software quality

Objectives of cost of software quality metrics

• Control budgeted expenditures
• Previous year’s failure costs

The classic model of cost of software quality

• Costs of control
• Costs of failure of control

An extended model for cost of software quality

Application of a cost of software quality system

• Definition of a cost of software quality model and array of cost items specifically for the organization, department, team or project
• Definition of the method of data collection.
• Application of a cost of software quality system, including thorough follow-up.
• Actions to be taken in response to the findings produced.

Problems in the application of cost of software quality metrics

• Inaccurate and/or incomplete identification and classification of quality costs
• Negligent reporting by team members and others
• Biased reporting of software costs, especially of “censored” internal and external costs
• Biased recording of external failure costs