4.2 MoSCoW Rules
Prioritization has been mentioned several times before. Since DSDM projects are
concerned to be in time and on budget, and since the users are heavily involved into
the development process, it’s mandatory to keep a constant watch on which features
the user needs most. There are two reasons a user might change his opinion during the
process, either he becomes aware of new technical possibilities or his work
environment changes. In both cases a quick re-evaluation of the priorities is required,
quick meaning, easy and straight forward classification of features into groups of
different importance. The DSDM techniques to weight importance are the MoSCoW
rules:
4.2.1 Must have
All features which are classified in this group must be implemented. These features
are a show stopper if they are not delivered, the system would simply not work.
4.2.2 Should have
Features of this priority are important to the system and contribute a significant value,
but can be omitted if time constraints endanger the delivery of any “Should have”
feature.
4.2.3 Could have
These features enhance the system with functional items, which can easily be reassigned
to a later timebox.
4.2.4 Want to have
Usually these features only serve a limited group of users and are of little value.
This classification system serves as single source of decision on what to implement
during the project and timebox iteration, it intentionally does not include any wish
list, because whish lists without classification, and hence without a price are no good
indicator for developers what users need most from their product.
4.3 Prototyping
Endorsing evolutionary prototyping DSDM projects satisfy two of the DSDM
principles, frequent delivery and incremental development. Prototypes are to
implement critical functionality fist to discover difficulties early in the development
process, they also allow having very early deliverables to get user feedback. If an
evolutionary prototyping is executed, the incremental nature allows for enhancing a