Feasible means that the implementation of a requirement shall be possible within given constraints:
- Technical feasibility
- The required technology is available to us
- Business feasibility
- We have necessary skills and experience
- We can implement the requirement
- We can implement the requirement within given timeframe
- Financial feasibility
- We have sufficient financial resources to proceed
Why do we need feasible requirements?
If the requirement is not feasible but accepted it may rise the expectation of the requestor that the provided functionality or performance will be provided.
The replacement control system shall be installed with no disruption to the production.
This is an unrealistic expectation. There will always be some disruption; therefore it would be better to state the requirement in the following way:
The replacement control system shall cause no more than 6 hours disruption to the production.
- To avoid unfeasible requirements involve the lower level architects/designer during the requirements elicitation process.