How long does a software project take?

What Determines the Duration

Clarity of Requirements. It’s not about whether they are written down, but whether the special cases have been thought through. "What happens in the case of a partial cancellation?" is the type of question that can extend a project by weeks if it only arises during implementation.

Speed of Decision-Making. If a query regularly waits a week for a response, the duration doubles—regardless of everything else. This is the most underestimated factor.

External Systems. Each integration also depends on the schedule of the other provider. Waiting for interface documentation can take longer than the implementation itself.

What Does Not Significantly Determine the Duration

The number of screen forms. Twenty similar forms are built faster than five with their own logic.

Planning Realistically

Use ranges instead of single numbers, and allocate time for things that are not included in any estimate:

• Testing by the later users
• Data migration and cleansing
• Training
• Corrections after the first real use

These four items typically account for a significant portion of the overall effort and are missing in most schedules.

What You Can Accelerate

A fixed contact person with decision-making authority, early designated test users from daily operations, and the willingness to limit the scope. All three cost nothing and have a greater impact than any technical decision.