Requirements gathering is an essential part of software development. However, the process can be difficult. To help you, we've assembled a detailed guide of the best methods for facilitating the requirements gathering process. Not merely a collection of links, our guide has detailed descriptions to help you maneuver.
We value your input. As always, if you know of an article, tip, tool or successful method for requirements gathering that should be included, send us an email with the information.
Prototypes range from the simple to the elaborate. But whether it's a paper sketch or an interactive digital design, a prototype should aid stakeholders and developers in anticipating requirements for a product.
- What is prototyping?
- Effective Prototyping for Software Makers -- Chapter 2, The Effective Prototyping Process: Prototyping is a process anyone can learn and master, according to author Jonathan Arnowitz. In this book excerpt, he describes the four phases of the prototyping process -- plan, specification, design and results -- and how you can use prototyping to communicate software requirements, designs and ideas.
- Create screen prototypes for clear software requirements: A step by step approach to communicating with your customers and getting the most out of your prototypes.
- Extending the benefits of prototyping: Great advice for those experienced in prototyping who have demanding customers, or who simply need a few new ideas.
- Prototyping and the software development cycle: The article may be old (the information is largely from 1992) but for those approaching prototyping for the first time, or for those who need a refresher, the combination of elemental information and good writing is hard to beat.
- Using paper prototypes to manage risk: Using a real-life scenario, the authors explain why and how paper prototypes can be ideal for risk management in a time crunch.
- Looking back on 16 years of paper prototyping: With all of the changes and advancements over the past 16 years, the authors explain why paper prototypes are relevant and beneficial in technology today.
Storyboards help developers visualize the sequence and interconnectedness of their work. They allow for a "big picture" approach that may be very useful in requirements gathering.
- What is a storyboard?
- User Interface flow diagrams (storyboards): The Agile answer to storyboards.
- Use cases and stories: An explanation of the differences between use cases and the stories of Extreme Programming (XP).
- Tips for Agile project management
- The latest predictions for Agile testing and development
- Discover new Agile testing software trends
A model can be made according to Unified Modeling Language (UML) or according to domain-specific modeling. Or, models can consist of stick figures on a whiteboard. All of these methods have their advantages and disadvantages. Use these links to figure out what method is right for you.
- The value of modeling: This white paper is an introduction to modeling, why it should be employed and the very basics of beginning software modeling. (PDF)
- UML for the software developer, Part 1 -- Building classes: Concentrating on three UML model diagram types, the author demonstrate how UML classes relate to code. There are diagrams and code examples to aid the reader.
- UML for the software developer, Part 2 -- Mastering associations: The second part of this series explains how developers can understand the relationships among classes in UML.
- Domain-specific modeling -- Welcome to the next generation of software modeling: The author lays out the shortcomings of UML and argues for DSM. By increasing abstraction, he argues, we reduce complexity.
- Test your knowledge of unified modeling language
Modeling in the agile methodology
While these links discuss modeling from an agile software development perspective, the lessons may still be valuable to those practicing other methodologies. At the very least, one can gather ideas for one's own modeling processes.
- Agile requirements modeling example: A detailed outline of requirements modeling from an agile standpoint.
- Software modeling on plain old whiteboards (POWs): The benefits of whiteboards may appeal to developers across the board. This article describes how to take good photos of whiteboards to preserve the information for when it is inevitably wiped off.
Tools to help with Agile requirements
Need drag and drop story mapping? Bauer has a JIRA plug-in tool for visual presentation and editing.
Online sticky notes are another great option, particularly when teams are distributed. Lino allows everyone on the team to chime in.
Other story mapping options include cardboardit and featuremap.
- Comparing the various approaches to modeling in software development: This is a clear, succinct overview of modeling approaches, paradigms and estimated adoption rates. A handy graph lays it all out.
- Simple tools for software modeling: Post-Its, index cards and whiteboards are extolled in this article, but CASE tools are discussed as well. The author lays out the benefits (and disadvantages) of CASE and offers suggestions for selecting CASE tools.
State transition diagrams
State transition diagrams allow developers and users to see how a program might behave. This anticipation of events is useful when discussing requirements.
- What is a state diagram?
- State-transition diagrams: This article explains what state transitions are and why they are important. Also included are a series of questions for testing state-transition diagrams.
- Automating state transitions: The Microsoft Developer's Network state transitions within Visual Studio. Code examples aid the reader.
- Visual Requirements: There is a section devoted to state transition diagrams in this article on diagrams in software development. The author provides a clear perspective on state diagrams and the necessary part they play among the other diagrams. (PDF)
- Understand testing diagrams
Use cases are created to capture functional requirements in the software development lifecycle.
- Software requirements analysis: Five use case traps to avoid: Employing use cases during software requirements analysis helps you improve your chances of developing software that truly meets their needs. But there are traps you should avoid, says expert Karl E. Wiegers, Ph.D.
- Planning requirements for multiple software product releases: Most software products evolve over time. The challenge is creating a release strategy that provides the maximum customer value consistent with budgets, schedules, resources and business objectives. This article written by Karl E. Wiegers describes two techniques for planning such release strategies.
- Use-Case Model -- Writing Requirements in Context: A well-written use case is an excellent tool in the requirements gathering process. This chapter is a great primer on creating use cases. (PDF)
- Listening to the customer's voice: Understanding the customer's needs is crucial in requirements gathering. This article explains how use cases can facilitate communication with users.
- Functional requirements and use cases: The connection between functional requirements and use cases is clarified in this white paper. A use case template and diagram are very helpful visual resources, the template in particular. (PDF)
Here are some tools that may prove useful in the requirements gathering process.
- Agile requirements gathering with user stories: ExtremePlanner is designed to help agile developers organize user stories.
- Requirements management for software engineering: Borland's DefineIT and CaliberRM are well-known requirements tools.
- stpsoft requirements storyboarding for Visual Studio: A storyboarding product designed for the VS Team System.
- My Little UML (Tools) Page An excellent Web site for UML tools. There are long lists - complete with descriptions - of open-source and commercial tools the author has had experience with and a list of commercial tools the author hasn't used. In addition, there's a little list of UML tools that are defunct for those who aren't quite up to date.
Other useful resources
- Ambiguous software requirements lead to confusion, extra work: Ambiguous requirements lead to confusion, wasted effort and rework. This article from software requirements expert Karl E. Wiegers, Ph.D. describes several common types of requirements ambiguity and suggests how to avoid them.
- Software Requirements, Second Edition -- Chapter 7, Hearing the Voice of the Customer: The heart of requirements engineering is elicitation, the process of identifying the needs and constraints of the various stakeholders for a software system. In this book excerpt Karl Wiegers, Ph.D. addresses the general principles of effective requirements elicitation.
- User Requirements for Software Development: This is a four-day course on requirements gathering.
- Requirements Engineering Journal: Yes, there is a journal devoted entirely to requirements.
- Writing Effective Use Cases: Alistair Cockburn advises readers how to write -- as opposed to model -- use cases in this book.
- Managing Software Requirements: A Unified Approach: Dean Leffingwell and Don Widrig emphasize team skills in this book.
- Requirements Gathering Essentials: Blogger Martin Bauer introduces and runs through the most important topics involved with requirements gathering. This page is for beginners and any developers who need a "big-picture" refresher on requirements gathering.
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