Problems of poor software documentation

Problems to your business (or your clients' businesses) that are caused by low-quality software documentation (or lack of documentation) include:

Processes and procedures may be ill-defined, not optimum or even wrong
Only experts can understand your software documentation
New people take a long time to train
You can't use temporary staff because they take a long time to train
If your resident expert ('power user') leaves, your staff may have difficulties in using advanced features of the software, because their informal expert advisor is no longer available
Customers have difficulties in using new software products