DSDM - Dynamic Systems Development Method Notes PDF

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Summary

Lecturer: Tom O'Kane
These are notes for the topic of DSDM...

Description

Agile DSDM – Dynamic System Development Method: DSDM is focuses on information systems projects that are characterised by tight schedules and budget constraints MoSCoW for scope prioritisation: -

Musts Shoulds Coulds Won’t haves

Fundamental Idea:

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Traditionally functionality was fixed and time and resources would change to ensure the functionality was achieved DSDM -> time and resources are fixed and functionality changes to ensure time and resource constraints are met

Note: DSDM has pre-project and post-project phases but main part is the project lifecycle embedded within the model

5 Phases of DSDM Project Lifecycle: 1. 2. 3. 4. 5.

Feasibility study Business study Functional model iteration Design and build iteration Implementation

 First 2 are done once sequentially, only once  Last 3 are iterative and incremental

Agile

1. Feasibility Study Phase: -

Decision is made whether or not to use DSDM Is it possible to do this project? What re the risks? Two outputs: o Feasibility report o Outline of development plan

2. Business Study Phase: -

Recalling what project needs we want to fit to limited time and resources o Workshops are organised to consider and prioritise project needs 3 outputs: o High level design of processes to be followed  ERDs, Business Object Models o System architecture definition  First system architecture sketch – allowed to change throughout o Outline prototype plan  State prototyping strategy for following stages

Agile 3. Functional Model Iteration Phase: a. Identify a functional prototype:  Analyse requirements  List requirements of current iteration  List non-functional requirements  Create a functional model b. Agree the schedule:  Determine the time required for the prototype and agree with the team and customer c. Create the prototype:  Based on functional prototype d. Review the prototype:  Includes testing the prototype and integration with other functions -

Outputs: o A functional model  Prototype code  Analysis models o Prioritized functions o Prototype review documents o Non-functional requirements identified o Risk analysis performed

Agile 4. Design and Build Phase: a. System is mainly built but the functionality components from earlier phase are now integrated to produce a complete system b. Identifying the functional and non-functional requirements that need to be in the system c. Agree the schedule d. Produce the system: integrate system components e. Review the system: system testing and review -

Outputs: o A tested system o User documentation f.

Functioning prototypes are reviewed by customers and further requirements may be found i. And will results in further iterations

Agile 5. Implementation Phase: a. b. c. d. e. f.

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System moves from development to production User training is done System implemented at user site Handover to customers Review is held to ensure system meets business needs The phase may require several iterations if… i. A wide number of users ii. Implementation is done over an extended period of time Outputs: o Delivered system o Project review report o User manuals and trained users

Outcomes of DSDM: 4 possible outcomes: 1. All requirements are met o No further work 2. Large number of requirements not met o Re-run process from start 3. Low priority (less critical) requirements not met o Re-run starting from functional model iteration 4. Some requirements not met due to time constraints o Re-run starting from design and build phase

Roles in DSDM: 1. Developers:  Only development role o Includes testers, analysts, etc. 2. Technical co-ordinator:  Defines architecture and owns technical quality 3. Ambassador User:  Most important user role  Bring the users views/knowledge to project and report back to users

Agile 4. Visionary:  User with most accurate knowledge of business requirements 5. Executive Sponsor:  Representative of the user company who has financial and ultimate decision making authority

DSDM Practices and Principles:         

Active participation is vital Teams must be empowered to make decisions Short delivery lifecycle Fitness for business purpose Iterative development All changes can be undone Only freeze core requirements at high level Continual testing Compromise and cooperate...