Adding additional fields to screens and customising a few reports can generally be done fairly rapidly.

However, integrating information such as orders and sales history from external systems can require that custom import utilities be developed.

Issues such as whether the import is batch-based (i.e. runs on a cycle, say once a day) or on-line (i.e. instantaneous bi-directional synchronisation with a remote database) also affect the degree of complexity. Such integration can often add significant time to a typical implementation.