Software crisis

Software crisis is the term used (first at the 1968 NATO Software Engineering Conference) for the situation in which software projects regularly ran over budget, finished late, failed to meet user needs and were unreliable and hard to maintain, while the demand for new and larger software grew much faster than the ability to build it.

Symptoms of the software crisis

• Projects run over budget and behind schedule.
• Delivered software does not meet the user's real requirements.
• Software is of low quality: many bugs, crashes, poor performance.
• Code is difficult to maintain, modify or extend.
• Many projects are cancelled or never used after delivery.
• Developer productivity does not keep pace with demand, so there is a large backlog of software waiting to be built.

Main causes

1. Rapid growth in the size and complexity of software.
2. Unclear and changing requirements; poor communication between users and developers.
3. Poor estimation of cost and time, and weak project management.
4. Use of an informal "code-and-fix" approach instead of a systematic process.
5. Inadequate testing and quality assurance.
6. Lack of trained people and of standards and tools.

Example

The London Ambulance Service Computer-Aided Dispatch (LASCAD) system (1992) was meant to automate the allocation of ambulances to emergency calls. It was built on a very tight schedule, with incomplete requirements, little user involvement and incomplete load testing. Soon after it went live it could not cope with the real call volume: calls were lost or duplicated, ambulances were sent late or to wrong places, and patients waited far longer than normal. Within days the service had to go back to a largely manual system. The project was late, over budget, unreliable and did not meet its users' needs, which shows every symptom of the software crisis.

A smaller, familiar example: a college result-processing system that is delivered months late, gives wrong grade totals because a rule was misunderstood, and needs costly rework every year when the grading rules change.

Response

The software crisis led to software engineering: a systematic, disciplined and measurable approach to developing software, using process models, proper requirements engineering, design methods, testing, quality management and configuration management.