Applying Software Metrics

What are Software Metrics?

Software metrics are quantifiable features of a software product or process. They can be classified as being one of two types:

• Process Metrics - are quantifiable attributes of the development or maintenance processes and their environment, for example time spent in requirements elicitation, degree of programmer experience
• Product metrics - are quantifiable features of the software product, for example number of defects detected since release.

Both process and product metrics may be further categorised as:

• Result Metric - quantifies some attribute of a completed project, or part project
• Predictor Metric - is used to make an estimate of the value of a result metric.

Why are they useful?

Two of the most fundamental reasons for measuring software are to control the processes of software production and to indicate the quality of the product. Both of these impact on delivering the project in budget, on time and to the required quality.

Measurement is essential for quantitative risk assessment, management and reduction. Thus providing the information to support quantitative managerial decision-making and reliability predictions.

Increasing the control and monitoring of software projects and maintenance tasks enables project managers, through assessments and predictions, to make reliable decisions during the software life cycle.

What metrics should be collected?

The metrics collected should relate to business priorities - quality, time-to-market, cost etc. These will vary from one organisation to another, but the metrics programme should not be seen in isolation. It should be integrated into management strategy and support the delivery of value from IT.

How to set up an effective metrics programme.

The collection, analysis and application of software metrics is SMS core expertise. Talk to one of our Principal Consultants for quality, business-focussed advice, or ask about the SMS Functional Size Measurement Pilot Study - a quick and inexpensive way to trial the benefits of functional size measurement in your organisation.