Feature Driven Development (FDD) definitions
- Feature Driven Development (FDD) uses a prescriptive model where the software development process is planned, managed, and tracked from the perspective of individual software features.
- Feature Driven Development (FDD) uses short iterations of two weeks or less to develop a set amount of features.
- A project team following the FDD method will first develop an overall model for the product, build a feature list and plan the work.
- The team then moves through the design and build iterations to develop the specifications.
Feature driven development (FDD) steps
- The five step Feature Driven Development (FDD) process is :
- Develop overall model;
- Create the features list;
- Plan by feature;
- Design by feature;
- Build by feature.
- [Agile Software Development: The Cooperative Game – 2nd Edition. Alistair Cockburn.]
Develop Overall Model
- The FDD project starts with a high-level walkthrough of the scope of the system and its context.
- Next, detailed domain models are created for each modelling area by small groups and presented for peer review.
- One or more of the proposed models are selected to become the model for each domain area.
- Domain area models are progressively merged into an overall model.
- DOMAIN OBJECT MODELING
- the team explores & explains the business environment of the problem to be solved
- DEVELOPING BY FEATURE
- breaking functions down into two-weeks or shorter chunks and calling them features
- INDIVIDUAL CLASS OWNERSHIP
- areas of code have a single owner to warrant consistency, performance and conceptual integrity.
- FEATURE TEAMS
- dynamic teams evaluating multiple design options and risk associated to those options
- reviews to help ensure good-quality design & code
- CONFIGURATION MANAGEMENT
- labeling code, tracking changes as managing the source code (ITIL)
- REGULAR BUILDS
- through regular builds, the team makes sure the new code integrates with existing code
- VISIBILITY OF PROGRESS AND RESULT
- process tracks progress based on completed work
Build feature list
- Knowledge gathered during the initial modeling is used to identify a list of features by functionally decomposing the domain into subject areas.
- Subject areas each contain business activities, and the steps within each business activity form the basis for a categorized feature list.
- Features in this respect are small pieces of client-valued functions expressed in the form ”
Plan by feature
- After the feature list is completed, the next step is to produce the development plan and assign ownership of features (or feature sets) as classes to programmers.
Design by feature
- Design package is produced for each feature.
- A chief programmer selects a small group of features that are to be developed within two weeks.
- Together with the corresponding class owners, the chief programmer works out detailed sequence diagrams for each feature and refines the overall model.
- Next, the class and method prologues are written and finally a design inspection is held.
Build by feature
- After a successful design inspection for each activity to produce a feature is planned, the class owners develop code for their classes.
- After Unit Testing (UT) and successful code inspection, the completed feature is promoted to the main build.
FDD Best Practices
- Feature-driven development is built on a core set of software engineering best practices aimed at a client-valued feature perspective.
- Domain Object modelling.
- Domain Object modeling consists of exploring and explaining the domain of the problem to be solved.
- The resulting domain object model provides an overall framework in which to add features.
- Developing by Feature.
- Any function that is too complex to be implemented within two weeks is further decomposed into smaller functions until each sub-problem is small enough to be called a feature.
- This makes it easier to deliver correct functions and to extend or modify the system.
- Individual Class (Code) Ownership.
- Individual class ownership means that distinct pieces or grouping of code are assigned to a single owner.
- The owner is responsible for the consistency, performance, and conceptual integrity of the class.
- Feature Teams.
- A feature team is a small, dynamically formed team that develops a small activity.
- Multiple minds are always applied to each design decision, and multiple design options are evaluated before one is chosen.
- Inspections are carried out to ensure good quality design and code primarily by the detection of defects.
- Configuration Management.
- Configuration management helps with identifying the source code for all features that have been completed to date and maintaining a history of changes to classes as feature teams enhance them.
- Regular Builds.
- Regular builds ensure there is always an up-to-date system that can be demonstrated to the client and helps highlight integration errors of source code for the features early.
- Visibility of progress and results.
- Managers steer a project using frequent, appropriate, and accurate progress reporting from all levels inside and outside the project based on completed work.
- Domain Object modelling.
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Updated : 24/10/2021