The Challenges of Agile Requirements

The agile philosophy places a strong focus on flexibility and adaptability. This means that the requirements often have to be changed during the product development. Changes can lead to initially defined requirements having to be revised or even discarded. Another challenge can be communication between the various stakeholders.

Prioritizing these requirements is often difficult. Various influencing factors such as company value, complexity, risk, effort, hierarchical and company policy factors, costs, and time constraints must be considered. The scope of the documentation should be tailored to the agile environment to avoid waste in line with the lean concept.

The Path through the Jungle: 6 Strategies for Requirements Engineering

Various strategies and methods can be used to overcome these challenges. These include:

1. Clear definition and documentation of the system thinking (determine system boundaries, identify influencing variables, delineate subsystems, identify interfaces between subsystems to relevant surrounding systems, analyze and identify commonalities in the delineated subsystems). It is crucial to precisely define and document the system for which the requirements are elicited. Unclear, contradictory, or incomplete requirements often lead to misunderstandings and misinterpretations.

2. Effective elicitation of requirements: Suitable methods should be chosen to elicit requirements (e.g., document analysis, self-writing, interviews, questionnaires, workshops, Gemba walk, etc.) to ensure that all relevant requirements are captured. Changing requirements can disrupt the development process and lead to delays.

3. Adequate documentation of requirements: The elicited requirements should be adequately documented (e.g., the 3 perspectives of requirements: Data perspective, functional perspective, and behavioral perspective) in order to avoid misunderstandings and create a clear basis for communication. This is crucial to ensure traceability and quality. Good documentation has the following characteristics: correct, clear, complete (within the agile planning horizon), consistent, prioritized, verifiable, modifiable, and traceable.

4. Verification and validation of requirements: Requirements should be checked for consistency and validated to ensure that they are feasible and legally permissible. All stakeholders agree upon the acceptance criteria, and there is a common understanding of them.

5. Prioritization of requirements: A method for prioritizing requirements should be used (examples could be preference matrix, utility analysis, Eisenhower matrix, MoSCoW method, WSJF, RICE, etc.) to ensure that the most critical requirements are processed first. This is because setting priorities is crucial but often complex and fraught with conflict.

6. Implementation in backlog items: As part of the ongoing refinement process, the requirements are broken down into smaller, actionable tasks (known as product backlog items, or PBIs for short) to facilitate implementation. These are split up jointly by the product owner, business analyst, and developer according to the INVEST principle (story slicing).