1. Requirements Engineering in Agile Tricode Professional Services www.tricode.nl 28-05-2010 Madalina Cerchia

2.

• Developers are NOT the bottleneck:

• • Faster machines with Gigaspaces

• • Better languages: Java, Ruby, Scala

• • Better tools: IntelliJ, Eclipse

• • Better practices: Test-Driven Development, Pair Programming, SCRUM

• Less rework- > more productivity

• Lean thinking-> less code (1)

• (1) Allan Kelly, Changing Software

The bottleneck has moved

3. Bottleneck is Requirements

• Requirements errors are the greatest source of defects and quality problems

• Most of errors originate in requirements and design activity

• Only 5% originate in programming

• Fixing requirements errors eats up roughly one-third (2) of your project budget

• Requirements are NOT a document:

• • Dialogue

• (2) Hooks and Farry 2001

4. Scrum process

• Each iteration begins with good requirements

5. Requirements challenges in Agile

6.

• Challenge 1: Does the business know what it wants?

• Ill know it when I see it

• New domain

• Highly innovative product

7.

• Challenge 2 : Working software over comprehensive documentation

• Agile doesnt mean that you dont need requirements

• Agile means you successively elaborate requirements

• Just-Good-Enough requirements

8. Challenge 3 : Dependencies between geographically distributed teams

• More difficult to coordinate work activities between teams

• Does a User Story provide enough context?

9.

• Business, Analysts and Designers work a Sprint ahead of the development

• Write Use Cases when its needed (alternative scenarios)

• Development teams should coordinate their activities

Possible solutions:

10. How to gather requirements -best practices-

11.

• Capture the the Big-picture

• Artifacts: Data Flow Diagrams

Agile practices to gather requirements (1/4)

12.

• Data Flow Diagram (DFD) - used to visualize the flow of data in a given context.

• Common applications:

• • Design of an existing business process

• • Define the upfront roadmap

• Common misapplications:

• Over specification by "drilling down" into sub processes with more DFDs.

• Tool: white board, CASE tools, Visio, etc.

• Example:

13. Order Processing Data Flow

14.

• Identify Use Cases- define how the new product will work

• UML Artifacts: Use Cases Diagram

Agile practices to gather requirements (2/4)

15.

• Use Case Diagram (UCD) - graphical overview of the functionality provided by a system in terms of actors and their goals ( use case )

• Common applications:

• Analysis of system functions that are performed by which actor

• Common misapplications:

• Identification of usage requirements

• Example:

16. Manage Users Use Case diagram

17.

• Model a bit ahead- focus on individual Use Cases for the first release

• Artifacts:

• • Business Process Diagram (BPM)

• • Domain Model Diagram (DMD)

• • State Diagram (SD)

Agile practices to gather requirements (3/4)

18.

• 1. Business Process Diagram (BPD)- provides a notation that is intuitive to business users yet able to represent complex process semantics

• Common applications:

• Identifying the business process in an intuitive manner

• Common misapplications:

• Document technical requirements

• Example:

19. Register Appointment Business Process

20.

• 2. Data Modeling Diagram (DMD)- shows relationships between entities within system, domain etc.

• Common applications:

• Explore domain concepts with project stakeholders

• Common misapplications:

• Complete data models up front!

• Simple tool:

• White board, Enterprise Architect, Visio, SmartDraw, etc.

21.

• 3. State diagram (SD)- describes the behavior of complex object

• Common applications:

• Analyze a complex business process

• Common misapplications:

• Design the behavior of several objects

• Design the behavior of a simple object

• Example:

22. Application releases- state diagram

23.

• Preliminary design mockups prototyping

• • document navigation, usability, look & feel without investing the time and money to develop the entire products

• Tools: Balsamiq Mockups, iRise

Agile practices to gather requirements (4/4)

24. Useful resources

• http://www.agilemodeling.com/

• http://modernanalyst.com/

• http://www.omg.org/spec/UML/2.2/