DSDM
Dynamic systems development method (DSDM) is an agile project delivery framework, first released in 1994. It was created to bring discipline to rapid application development (RAD), which had spread through the industry in the early 1990s as graphical tooling made prototyping practical. RAD was popular but unstructured, and the consortium that founded DSDM – vendors and practitioners from companies such as British Airways, Oracle, and Logica – wanted a shared, vendor-independent framework that retained RAD’s speed without sacrificing quality. In later revisions the method was generalized beyond software into the DSDM Agile Project Framework, a generic approach to project management and solution delivery. It is now owned and administered by the Agile Business Consortium, the not-for-profit successor to the original DSDM Consortium.
DSDM’s distinguishing constraint is that it fixes cost, quality, and time at the outset, and treats scope as the variable. Work is prioritized with the MoSCoW technique – must have, should have, could have, and won’t have – so that when time or budget runs short the lowest-priority requirements are dropped rather than the deadline slipped. This inverts the assumption of plan-driven methods such as the waterfall model, where scope is fixed and schedule flexes. The Pareto principle underpins the approach: roughly 80% of the business value comes from 20% of the requirements, so delivering the most important increments on time is expected to meet the need even when the rest is deferred.
The framework is iterative and incremental. Work is broken into timeboxes, each with a fixed budget and delivery date, and within each timebox the team iterates on a prioritized slice. Continuous user involvement is a core success factor – users test-drive prototypes and workshops gather stakeholders to agree on requirements and direction.
Principles
DSDM is underpinned by eight principles that direct the team’s mindset.
- Focus on the business need
- Deliver on time
- Collaborate
- Never compromise quality
- Build incrementally from firm foundations
- Develop iteratively
- Communicate continuously and clearly
- Demonstrate control
Core techniques
- Timeboxing. The project is completed incrementally in portions, each with a fixed budget and delivery date. Because time and budget are fixed, the requirements are the only remaining variable.
- MoSCoW prioritization. Work items are sorted into must have, should have, could have, and won’t have, so that scope can be trimmed to fit the timebox.
- Prototyping. Prototypes are built early so users can test-drive the system and shortcomings surface before commitment.
- Testing throughout. Testing happens in every iteration rather than as a final phase. The team is free to choose its own test management approach, as DSDM is tool- and technique-independent.
- Workshops. Stakeholders are brought together to discuss requirements, functionality, and mutual understanding.
- Modelling. Diagrammatic representations of the business domain and system improve shared understanding.
- Configuration management. With multiple deliverables under development in parallel and shipped incrementally, they must be tracked toward completion.
Compared with other agile frameworks
DSDM belongs to the same family as Scrum, Extreme Programming (XP), Crystal Clear, feature-driven development, and the Rational Unified Process. These methods share several traits: they prioritize requirements and work through them iteratively, they are tool-independent, they treat requirements rather than time as the flexible variable, and they emphasize stakeholder communication and involvement.
DSDM differs in emphasis. Where Scrum prescribes fixed-length sprints and specific ceremonies, DSDM fixes the project’s overall cost and deadline and lets scope flex via MoSCoW. Where XP prescribes technical practices such as test-driven development, DSDM is largely silent on engineering technique and leaves that to the team. The 2014 revision of the framework explicitly addresses interoperation with PRINCE2, ITIL, and PMI, reflecting its positioning as a project-management framework rather than a pure development method.