Functional Requirements 101: A Project Manager’s Guide

Your path to delivering a successful project runs directly through a list of functional requirements. Get this part right, and you are well on your way.

This guide provides a closer look at the two types of project functional requirements and outlines the steps a project manager should take to gather, document, and manage them effectively.

Functional versus Non-Functional Project Requirements.

Functional requirements are the software capabilities that the stakeholders or the business expect at the completion of the project. These are considered functional requirements. Sometimes they are referred to as the business requirements because these are the needs of the business or end user.

Once those are established, the technical team can create a list of non-functional requirements.  Sometimes, they are also referred to as the technical requirements because they list what it’s going to take on the technical side to properly execute the functional list.

Both types of requirements are equally important to your success. When you have a complete understanding of what is required on all sides, you reduce financial risk and increase the likelihood your project will be delivered on time and meet stakeholder expectations.

Why Are Functional Requirements Important?

Many project failures can be traced to an incomplete list of requirements. Often, it starts with a lack of communication. A project manager neglects to involve users, or they do not collect a complete list of requirements. That leads to confusion about what should be on the functional list, and that inevitably leads to an incomplete list of what the non-functional requirements should be.

A clear understanding of requirements also avoids scope creep and wasted time. For instance, if you aren’t clear about the mission, you may end up doing things that do not directly relate to the project. Or, if there is a misunderstanding and a portion of the project needs to be redone, your schedule will be interrupted, and your team members may become frustrated.

Requirements serve as the foundation for the design, development, and testing phases of the project, and define what success looks like.

How to Craft a List of Functional Requirements.

Your first step is to meet with the stakeholders and get very clear on what they want and need. Ask lots of questions and record the details. When you’re confident you know what your project’s mission is, create a list of the functional requirements. Run it past stakeholders to be sure you have captured everything.

Hand this list over to your technical team. They will take the functional requirements and figure out what is needed on the backside (technically) to make those functions operational.

Project functional requirements are the specific features and capabilities that the end product must have. For example, a customer hosting a conference will have specific needs such as the ability for attendees to register, pay for their entry, choose break-out sessions, and book a hotel. These specific features are the functionalrequirements of the project.

Using our example above, a list of functional requirements may look like this:

  • User registration and login
  • Documentation with a confirmation number
  • Receipts
  • Session Sign-ups
  • Mobile access to documents
  • Real-time document updates
  • Ability to book hotels and transportation from website
  • Integration with third-party tools

The Non-Functional Requirements for the above list might look similar to this:

  • Performance – response time of less than 3 seconds
  • Security – protection against hacking attempts
  • Usability – user-friendly interface
  • Scalability – ability to support at least 500 concurrent users
  • Availability – system must be available 99.9% of the time
  • Interoperability – integration with other systems and tools
  • Reliability – ability to recover from failures and provide data consistency
  • Maintainability – ability to upgrade and update the system easily
  • Compliance – adherence to relevant regulations and standards
  • Accessibility – ability to use the system by people with disabilities.

Best Practices for Writing Functional Requirements.

First and foremost, your language must be consistent and understandable. Do not use terms that are too technical or that could be interpreted in more than one way. The object is to make sure that everyone is on the same page and understands the project’s goals, regardless of technical expertise.

When a project manager takes the time to define in detail the functional requirements of a project, it’s much more likely the non-functional requirements will support the success of the project. They are two distinct categories, and they are both important to a successful outcome.