Both exercises produced similar results and showed that software development productivity was generally below industry standards, but:
■ productivity was higher under the partnership than previously, was improving more quickly than the industry, and, if trends up to 1997-98 continued, it would reach industry levels within five to ten years;
■ projects developing software for mid-range and client-server systems had higher productivity than mainframe projects; and
■ some projects with well-specified requirements and small development teams had met industry standards of productivity.
The studies also showed the rate of software delivery was closer to industry standards.
The studies identified a number of factors which may affect software development productivity in the partnership, including:
■ Complex requirements - many of the Department's systems are governed by tax legislation which is often complex and can change from year to year. This introduces complexity into calculations on top of stringent security requirements, aimed at maintaining taxpayer confidentiality.
■ Changes in requirements - changing requirements during software development can lead to time consuming rework. The Department's systems have often been subject to such changes.
■ Uniqueness of requirements - many of the Department's requirements are unique and it does not therefore have the same access to proprietary software as private sector organisations, increasing the need to develop bespoke systems.
■ Demand for system performance and availability - the Department relies on large systems to carry out its work. They must be designed to provide high performance and availability. They must also be tested thoroughly to ensure they function correctly when introduced.
■ Technical stability - most of the Department's existing national systems were introduced over a long period in response to legislation or major organisational change and therefore tended to be developed separately using different design philosophies and development tools. This reduced the opportunity to carry lessons over between projects and makes integrating new and existing systems more difficult.
■ Development timescales and team sizes - the relatively short times available to develop some new systems to meet legislative deadlines, such as self assessment, have encouraged the use of large development teams. The external report suggested that such teams deliver software only marginally quicker than smaller teams, but at significantly lower productivity and higher cost.
■ Development tools - the software development tools available for the ICL computer systems traditionally used by the Department have been more limited than those available for the open systems which it is now using.