Writing requirements well can be the make it or break it factor between a successful project and a failed endeavor. Why? Poorly written requirements can lead to costly mistakes and delays. Often, the reason behind that is scope creep, that is, when a project’s scope changes or grows in an uncontrolled way after the project has already started. Sadly, this is pretty common if the project scope is not well defined, documented, and controlled by high-quality requirements authoring from the start. Read on to learn more about what makes a strong requirement and our top tips for putting them together yourself!
The importance of requirements management
The key to setting up your product or project for success is writing and managing requirements as effectively as possible. Efficient requirements engineering involves brainstorming, documenting, analyzing, and prioritizing the requirements in a streamlined way. Requirements must also be traceable to support communication between all team members and stakeholders so that everyone involved in the project can track changes. If these steps are carefully followed, then there is a higher chance the project goals will be met.
Common mistakes when writing requirements
When kicking off your Requirements Management process, the first step is to create a requirements backlog i.e. write down the requirements. This is the main way of communicating or translating user needs to developers. This collection of requirements will also support communication between all your team members, developers, and stakeholders, and will help your organization save a ton of money. As a result, they need to be prepared very carefully. Although writing requirements is not a ‘technically’ difficult skill, there are many common mistakes like:
- Using incorrect or inconsistent terminology
- Making grammar mistakes
- Being too vague or ambiguous
- Being too specific and wordy
- Making false assumptions
- Describing how to implement something instead of what is required
What should a requirement contain?
Requirement engineers need to pay attention to the details and make sure they structure, phrase, and present requirements in the best way possible. Ideally, every requirement statement (written from the user's perspective) should:
- Contain a user role
- Explain how the user benefits from the requirement
- Outline the desired state that the requirement will help achieve
- If relevant, include metrics that allow requirement testing
A general rule of thumb is that a requirement should read like:
The ‘thing’ shall provide/do ‘something’ to achieve ‘desired result’.
8 tips for requirements management: best practices we recommend
In order to write effective requirements, you should make sure they are:
Ask yourself the “Three W’s”:
- What will we do?
- Why are we doing it?
- Who benefits from this?
If you can’t easily come up with answers to those questions, chances are you don’t have a full understanding of your users' needs. As a result, you might be including requirements that aren’t actually needed — leading to requirements bloat.
Once you have confirmed that a requirement is, in fact, necessary, you can go ahead and write it up. Now it is incredibly important to be as clear, direct, and unambiguous as possible. Simple sentences ensure that everyone reading them can understand their meaning in the same way. Here’s a couple of things you will want to avoid when phrasing your requirements:
- Using the passive voice
- Buzzwords, jargon, abbreviations, acronyms, or any terms that aren’t widely understood (if they can’t be avoided for some reason, don’t forget to include them in a glossary)
- Adverbs which can be interpreted in different ways (ambiguity)
- Negative phrases to outline what ‘shouldn’t’ be done (instead, describe what should be done)
- Vague expressions which are hard to test and verify
- Concise & consistent
Here’s a little trick for you: many people say that if a requirement can’t fit on a post-it note, it’s already too long. Think short and to the point for the best readability possible. This makes it a lot easier for stakeholders and developers to organize, absorb, and analyze the requirements of a project. That being said, don’t leave out something crucial either. Requirements should be as concise as possible while still fully conveying the information they need to.
Using inconsistent terminology when capturing requirements can cause confusion, mistakes, and delays. Creating a project glossary at the beginning of the project to define terms will help keep everyone on the same page. Make sure that all the terms are listed, do not contradict themselves, and that the user and developer language is aligned. Referring back to this glossary while writing the requirements will make sure the terms you use stay consistent and understandable for everyone involved.
This may seem pretty obvious, but it bears repeating. Just because you assume a requirement is needed does not mean the assumptions that you have made are actually accurate. Make sure the information included in the requirement is on point and that your stated assumptions are correct.
After confirming that the assumptions in the requirement are correct, you need to make sure that your statement is technically feasible. Start by taking a look at the project budget and timeline, then at the resources available to you. If the requirement can be practically implemented with the conditions at hand, then you’re good to go.
Requirements should be categorized by type and then prioritized. The exact categories do depend on your organization, but the main types of requirements are the following:
- Functional requirements
- Non-functional requirements
- Business requirements
- System requirements
Categorizing requirements makes it easier for stakeholders to read through them, manage them, and figure out which are most relevant to their roles. Then, prioritizing them in order of importance helps to accurately define a) the scope of the project and b) a schedule for implementing each one.
Another thing to bear in mind when structuring requirements is that they should be verifiable. In other words, it needs to be possible to test the system to show that it meets the requirement in question. This is another reason that requirements should be as clear and unambiguous as possible. If it is full of vague terms like ‘maximize’ or ‘minimize’, ‘easy’, ‘flexible’, or ‘safe’ for example, it becomes harder to concretely verify via analyzing system performance. It also ties in with the next important aspect – traceability.
Requirements traceability refers to making sure that there are links between requirements and other entities in the project. This allows project managers, developers, and stakeholders to document and track the whole lifecycle of a requirement in all directions and in relation to other components. With traceability adequately managed, you won’t have ‘stray’ code (that is, code not related to a requirement), and you’ll be able to track if all your requirements are covered by test cases. In order to make requirements traceable, they should always be labeled with a unique identifier and their source information should always be filled out. All this needs to be carefully tracked in a shared central repository accessible to all your team members.
This is incredibly important for change management and compliance purposes. It also helps to understand the scope, complexity, and impact of changes. Finally, traceability allows you to identify any inconsistencies, gaps, or errors in the carrying out of requirements.
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Although not technically difficult, putting requirements together in the best way possible can be a challenging endeavor. After all, getting it right can mean the difference between your project sinking or soaring. Looking for more guidance on how to write excellent requirements for your projects?