Assuming that the SaaS application to be documented is directly accessible to end users, the user manual will contain:
a. Overview of package capabilities;
b. A set of use case descriptions, showing how the user will use the package in normal operations.
c. Description of each individual function or feature, including legal input domains and output ranges.
d. A listing of error messages, indicating the reason for each message and what the user needs to do to correct the problem that caused the error to be detected.
Project milestones:
a. Draft of entire user manual, delivered for client review and comment.
b. Final delivery of manual, edited in response to client comments, posted using tools to be supplied by client.