Developing Requirements for Enhancement and Replacement Projects

Technique

Why it’s relevant

Create a feature tree to show changes

• Show features being added.

• Identify features from the existing system that won’t be in the new system.

Identify user classes

• Assess who is affected by the changes.

• Identify new user classes whose needs must be met.

Understand business processes

• Understand how the current system is intertwined with stakeholders’ daily jobs and the impacts of it changing.

• Define new business processes that might need to be created to align with new features or a replacement system.

Document business rules

• Record business rules that are currently embedded in code.

• Look for new business rules that need to be honored.

• Redesign the system to better handle volatile business rules that were expensive to maintain.

Create use cases or user stories

• Understand what users must be able to do with the system.

• Understand how users expect new features to work.

• Prioritize functionality for the new system.

Create a context diagram

• Identify and document external entities.

• Extend existing interfaces to support new features.

• Identify current interfaces that might need to be changed.

Create an ecosystem map

• Look for other affected systems.

• Look for new, modified, and obsolete interfaces between systems.

Create a dialog map

• See how new screens fit into the existing user interface.

• Show how the workflow screen navigation will change.

Create data models

• Verify that the existing data model is sufficient or extend it for new features.

• Verify that all of the data entities and attributes are still needed.

• Consider what data has to be migrated, converted, corrected, archived, or discarded.

Specify quality attributes

• Ensure that the new system is designed to fulfill quality expectations.

• Improve satisfaction of quality attributes over the existing system.

Create report tables

• Convert existing reports that are still needed.

• Define new reports that aren’t in the old system.

Build prototypes

• Engage users in the redevelopment process.

• Prototype major enhancements if there are uncertainties.

Inspect requirements specifications

• Identify broken links in the traceability chain.

• Determine if any previous requirements are obsolete or unnecessary in the replacement system.