Characteristics of good requirements – atomic

Atomic means that a requirement shall state only one request, functionality, or need.

Why do we need atomic requirements?

When multiple requirements are stated in one the risk increases that a requirement may be missed in the design. It can also lead to verification issues – it is difficult to provide a verification status for such a requirement, which confirms that this requirement has been implemented in the system. It may present problems in verification if the requirements have to be verified by different methods, at different times, or at different levels of assembly.

Example:

The system shall generate a batch report and a discrepancy report when a batch is aborted.

This requirement clearly states two requirements. It would be better to split this requirement into the following 2 requirements:

The system shall generate a batch report.

When a batch is aborted the system shall generate a discrepancy report.

Tips:

  • Avoid conjunctions (and, or) that make multiple requirements in one sentence.
  • When you have a conjunction in your requirement statement check how this influences the verifiability of the requirement. If the verifiability of the requirement is affected, consider splitting this requirement.

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