Ministry of Education CIO Leanne Gibson says keeping track of the testing effort as a percentage of overall development spend is an important metric, because it provides an indicator on effectiveness and efficiency in the application lifecycle management.

"Key areas of this cover project leadership, development effort, business analysis, testing (unit, release, integrations, UAT) and architecture/design," she says.

"Testing will vary, depending on the complexity and risk of the project. As an overall percentage, the range for test expenditure tends to be between 24 percent and 34 percent, based on an application lifecycle management approach. This includes costs arising from project management, business analysis, architecture/design, testing, development and other related project costs."

Accident Compensation Corporation acting CIO Jane Hardy says the nature, extent and cost of software testing depends on the specific project being carried out and can vary greatly between projects.

"Without investing the considerable time that would be required to analyse a sufficient number of completed projects to establish a statistically accurate average figure, it is difficult to provide a generic indication of software testing costs as a percentage of ACC's overall IT project costs," she says.