I once took over the management of a programme containing two application development projects. One was the development of an accounting package, the other the development of a spare parts sales system. When I joined the project I initiated a review of both projects, covering all the focus areas introduced later in this chapter. The review included the technical architecture and the way in which it had been implemented. I discovered that the spare parts sales system had some unusual features.

Record locking had not been fully implemented and it was possible for two operators to allocate the same instance of a part to two different customers. Also, transaction management had not been implemented at all, which meant that there was no way of rolling back an incomplete transaction that had failed. It also meant that, in the event of a serious failure of the system, all sales transactions completed since the previous dump of the database had to be re-entered manually before normal customer service could be resumed. It was not possible to recover automatically to the point of failure using the last dump of the database and the day s transaction log file.