Product Specification

A product specification describes all the requirements for building a product and guides your team throughout the product design and development process.

As your idea for your product takes shape, you need to document all the requirements for the build as guidance for your product team. This documentation needs to be clear and concise to give them an idea of the product’s needs, while not so technical that it forces them to work within tight constraints.

This document of requirements is known as a product specification. In this glossary article, we define what a product specification is, explore what it contains, and suggest a good approach for creating one.

What is a Product Specification Document?

A product specification document, or “product spec,” contains all the features, requirements, and high-level business goals of a product. With this information, a good product specification helps direct your product team to ensure they’re progressing in line with your business strategy and objectives.

The best product specs are concise, yet detailed. They contain as much information as possible about the functionality of the product and the kind of users that the product is positioned to serve. However, they don’t micromanage the details of implementing or developing the product—that should be left to your product team.

What is Included in a Product Specification?

The format and details of a product specification document will differ depending on the kind of product you’re working on. With that said, there are certain things that most product specs should include.


The first part of a product specification is the summary, which introduces the overall product idea, and includes:

The summary provides a high-level look at the product and an idea of what the final version will look like.

Business Case

The business case describes the benefits that the product will confer to the company. This may include how the product can improve your company’s market position or increase revenue. The business case also describes the resources necessary to develop the project. 

User Stories

User stories describe the product’s features and capabilities through short explanations from users’ perspectives. A sample format of a user story is:

“As a <user>, I can use <feature> so that <benefit>.”

One example of a user story for Netflix might be:

“As a viewer, I can add shows or movies to a favorites list so that I can watch them later.”

Your product specification will outline the features of the final product in the form of these user stories. It should also include user acceptance criteria, which are indicators that determine if your product actually meets the standards of each user story.

User Personas

Your team should always build your product focusing on fulfilling customer needs, not just ticking off a checklist of features.

User personas describe the target audience of the product—their characteristics, goals, and pain points. Having user personas in your product specification document, therefore, helps your product team stay on course with your product strategy and achieve better product-market fit.

Product Design

Your product spec should also contain a rough design of the final product. This could be a technical drawing of a physical product or key wireframes and screens for an app. 

In the product specification document, the product design is not intended to be an immutable, final design. It’s more of a reference to guide your product team in making the final design. In fact, your product design is likely to change as you go through the product development process.

Functional Spec

The functional spec is a document that describes what the product looks like, what it can do, and how users interact with it. This is a more technical part of the product spec, and you and your team will use it as their reference when they start building or programming.

How Do you Create a product Specification?

Making an effective product specification isn’t easy and requires an intimate understanding of everything about your product—from its features to its goals and users. You can use the following steps to guide you in making your product spec.

1. Define the Problem That Your Product is Addressing

So many products fail because they are “solutions in search of a problem.” You need to know that your product idea addresses a specific market need. Your product’s suitability for meeting that need will be what provides benefit to consumers, and that translates into sales.

To ensure that you’re on the right path when building your product spec, you need to identify a clear problem or pain point that your product will address in your target market. This will help guide your team towards making a truly customer-centric product.

2. Listen to Your Users

Creating user stories is only one part of the equation for understanding what your users want. You also need to engage with your customers directly and listen to their feedback. Conduct interviews and focus group discussions with members of your target audience. Have them test a prototype and ask their thoughts on the current features.

You should also look at what your customers have said about your existing products in a similar niche and what they’ve said about your competitors, as well. By getting a better understanding of what they specifically want, you can refine your product spec to include the features that they’re looking for.

3. Invite Your Company to Give Feedback

Aside from getting feedback from customers, you should also ask your company to look at your product. This greatly increases the number of eyes and perspectives you can use to identify design flaws.

It also makes your employees feel that they’re contributing to the product and strengthens their understanding of how the product development process will align with other departmental goals, as well as your overall business objectives.

4. Finalize Your List of Specifications

Your product specs won’t just include the product’s features. You also need to define important information like software support period, safety protocols, and compatibility with existing products. 

Talk to your product team and work out what these specifications are so that you can make a more effective document.

5. Be Ready to Revise

A good product spec is adaptable to user needs. You’ll be getting a lot of feedback throughout the process of building your spec, and you need to be ready to revise as necessary.

You should be ready to remove features entirely, change your product design, and overhaul the entire spec if it doesn’t meet market needs. By keeping it in line with what your customers want, your product spec will form the foundation of a strong product development process.

Every Great Product Has a Great Product Spec Behind It

In conclusion, Product specification documents ensure that your product team is aligned with your product’s targets. Without them, your product risks going out of scope or losing sight of the big picture. 

To optimize your product development process therefore always make sure that an effective product spec is a prerequisite for beginning work.