In general, a wrong computation can be duplicated after correction of the problem, lost data can be retrieved from a backup. If, however, the backup and archive system is malfunctioning, there is no rescue. This makes the support of a data repository system a very special challenge for both the software vendor and the customer. The risk emerging from malfunctioning software or inadequate operation is, however, at least as high. In every phase in the lifecycle of the product and its installation at a particular site, errors can contribute to a later disaster.
Complexity is the contribution of the design phase to the risks mentioned above.
Complexity in the software arises from the evolutionary design of the product and must be countered by evolutionary redesign. This is not a real scenario but its ingredients are realistic. The consciousness that they are vital is indispensable for the software vendor as well as for the customer. The data repository is particularly important. The data repository is particularly vulnerable.