How To Write The Design Specification? [Quick Guide]

19663 Updated 10.31.2022
Anna Holishevska

Design Team Lead at Northell


Table of contents

If you are not professional in product management and have never had to create a design specification before, then you have come to the right place. If the question of what specification means makes you think a lot, this article is written for you.   

While you may have mastered the fundamentals of writing design specifications, putting it into practice necessitates considerable thinking and dedication. Here’s an overview of what you need to know and how to write flexible and precise design specifications.

We will go through what design specs are and how they are used, as well as provide some instances of design specifications. You will learn what to put in your design specifications document, how to write design specifications and lots of other helpful information.

What is Design Specification? 

What is a design specification? What are specifications? These questions bothers lots of people and product owners. 

A design specification is a written document that explains your product and specifies what you want it to perform as well as how the user should interact with it. While it may seem laborious to write everything down, it is the most crucial thing you can do in the early stages of product design and development. This is because the design specs direct the whole scope of your product development. 

As the term suggests, a design specification is a document that outlines a project’s design needs. For the design team, this is a vital document since half of the success of a project depends on it. After extensive study, the document is created by the client and contains extremely comprehensive, specific design requirements that must be consistently applied until the project is completed. With such a list of requirements at hand, designers will be able to bring what the client sees to live. 

Why is Design Specification so important?


The importance of design specifications in the design process is well acknowledged. A set of requirements is used to describe the desired solution in the specification document. A detailed description of the desired solution is critical since it increases the chances of a successful design. In order to have a clear description, there must be enough requirement statements to take design engineers from the abstract to the concrete solution in order to achieve the product’s goal. 

The criteria for selecting a feasible concept are established in the form of a design specification, which is a collection of requirements that any solution to the problem must meet once it has been found. As a result, the function of the specification is twofold: first, to create a solution space for design engineers to work in when creating a product, and second, to evaluate proposed solutions to ensure that they are within acceptable bounds.

Why should you as owner write Design Specifications?

As a product owner, you should have a clear understanding of what the product should be like, how it should look like, how users should interact with it, etc. You are the only person who can clearly and in detail describe your future product’s desired characteristics. By drawing up a design specification document at the initial stage of product development, you can save time and money, create the perfect product that meets your expectations, make the process easier for designers, and much more.

The role of specification in the design process has an impact on its development. The specification is crucial in the product development process and it has been discovered to play a number of roles, including:

  • Designer guidance.
  • Identify the intercommunication between requirements.
  • Checklist, e.g., at meetings or workshops.
  • An agreement within the design team and as a contract with the customer, e.g., a supplier agreement, to perform the design task.
  • Trace the probability of propagation of change.
  • Product overview.

What does the Design Specification include?

Design specification document should include essential information about your product and all details you want your design and development team not to miss. 

Usually, the design requirements (specifications) document includes the following things:

  • Full project overview.
  • Main needs and goals.
  • Target audience.
  • Functional requirements and desired set of features.
  • Aesthetic aspects.
  • Non-functional details.
  • Recommendation and prohibitions.
  • Questions.

What is the difference between Software Specification and Design Specification?

A software design specification is a document that explains what the software will accomplish and how it will function. It also outlines the functionality that the product must have to meet all stakeholders’ needs (business and users).

The key elements of a software specification are:

  • Purpose.
  • Broad description.
  • Detailed requirements.

The greatest software specification documents describe how the software will interact with other software when it is embedded in hardware. Real-world users are also taken into account in good software specification documents.

Software Specification vs. System Specification

A software specification contains detailed descriptions of the software to be created.

What are system design and computer system design specifications? A system design specification is a document that contains information about a system’s requirements. 

The system design specification examples and software design specification examples you can simply find on the Internet.

Software Specification vs. Design Specification

A software design specs are usually written for developers and contains all information about how the future product should work. 

A design specification is all about how the product looks like, how attractive it is to users, how easy it is to navigate, etc. This document is usually written for design teams.   

According to Wikipedia, the design specification document’s columns and information can be changed depending on the output format (may be a physical product, or software, etc.)  

In case you want to get software design specification example, etc.

Our team will provide you with them.

How to Write a Design Specification? [Guide]

We have already discussed the design specification definition, which sections are included in a typical design specification and why you should use design specification. Now it is time to move to the writing process.  

Writing a design specification increases the likelihood of a successful project, service, or feature that all stakeholders appreciate. It reduces the likelihood of something terrible going wrong during implementation and even after launching your product.

Based on extensive experience in designing and developing products, the Northell team has prepared a detailed guide that will help you write useful, clear and detailed design specifications. You can also contact us for a design specification template. Let’s start!

Design Specification. Part 1 – Business Analysis

With the help of business analysis, it will be much easier for you to write detailed and helpful design specifications. After analyzing all the points that we give below, you will get a broader picture of your company and exactly what your future product should be.

#1 Write an overview of your project (what, how and why)

Before starting writing design specs, describe in detail your project. Provide basic information about your project, its size, main features and characteristics. The more detailed you describe your project, the easier it will be for the design and development team to imagine the future product and how it should look like.

#2 Set your main goals

Your business goals are the results that you hope to achieve and maintain as you run your business. As an entrepreneur, you are concerned with all aspects of your business and must have clear goals for your company. Having an exhaustive list of business goals creates guidelines that will form the basis for your business planning and play an important role in writing the design specification.

It is essential to think about what you want to achieve with your future product or how your future product will help you achieve your goals. Suppose you do not know what goals to achieve. In that case, it will be difficult for you to write the correct design specification and develop a beneficial and valuable product.

#3 Budget and time constraints

Why are budgeting and time constraints significant before writing system specifications? Having calculated how much money and time you can spend on a project, you can easily understand what to include in the system specification and what not. 

In general, if you plan everything right before starting to create a design specification document, the process of writing itself will become easy and understandable for you.

#4 Know your competitors

Your competitors are a valuable source of information for you. By knowing your competitors and comparing them, you can make your product competitive. You can find competitors and analyze them simply by searching in Google search. Browse their social media and analyze websites. You can also assess the ads your competitors are creating by entering keywords into the search bar. This will show you how much attention they are paying to marketing. 

#5 Selecting the target audience

In order to correctly write a user requirement document, you must know well those for whom you will design and develop the product. Do you know the user requirements definition? User requirements are statements in natural language with diagrams that describe the services the system is expected to offer to system users as well as the restrictions it must function under. 

In order to determine your target audience, you can analyze competitors, who use their products and services, who is a member of their community on Facebook or Linkedin, who leave positive reviews, etc. You can also check user requirements examples.

Collect about 50 such people and analyze them according to various parameters. This way, you will be able to form the ideal user for your product. In addition, check other user requirement specification examples (user requirement examples) or user requirement specifications templates on the Internet. 

#6 Industry uniqueness

Doing product research is a big aspect of writing design specs. You should conduct thorough market research on the industry in which your product performs. Medical equipment, technological devices, and children’s and baby products are just a few of the regulated industries.

Read news or media portals like Crunchbase and AngelList. Keeping up with all the latest news will help you not to miss new trends and innovations in various industries.

#7 Users needs and problems

In order to identify what problems and needs your users have, conduct surveys. Make a list of questions and topics that are important to you and conduct a poll. The more information you learn about your users, the easier it will be for you to write design requirements for them.

#8 System features

We can say that system features description is a part of the technical design specification and computer system designs. This specification in software engineering helps understand how the future product will work and its functionality. Make some lists with top, minor and least important features for your product. Analyze competitor products to create such lists. You can read reviews on product functionality, see ratings for ease of use, etc., on the G2 crowd. 

#9 Market Standards

At this last stage, you should think about which countries/regions of the world your product is intended to be released in? You should also specify the appropriate standards and regulations. But market standards are not only requirements on a regional basis. There are also must-have things your product should provide. For example, if your product is an online store, paying online is a must-have thing (or a market standard). But payment in cryptocurrency is over market standard. Therefore, it is essential to keep a balance in these things.

Business analysis is a rather difficult process and you cannot do without the help of professionals and experienced people in this matter. If you have any questions or need help with business analysis, you can contact us. We will answer any questions you may have!

Design Specification. Part 2 – Design Specification writing

After conducting a quality business analysis, you can start writing the design specifications. We have prepared a plan, which can be a little cheat sheet for you when writing design specifications. Let’s take a look at each step separately.

#1 Writing Full Project Review

The first step in writing a design specification document is describing your project, namely your future product. Give answers to such questions: why are you creating this product, what product do you want to get as a result, how do you think this product will be able to help users, what problems this product solves, how much time and money you can spend on this project, etc.

#2 Write your main goals

Describe the exact goals you want to achieve after the release of your product. Defining goals helps fill the product with things that will help you achieve those goals. Your goals should have certain criteria:

  • Clarity. 
  • Measurement in money and time (turnover, income and profit). 
  • Measurement in resources (human, etc.). 
  • Achieving marketing goals.

#3 Target client

Describe your ideal customer profile (ICP). Consider these characteristics to identify ICP:

  • Budget / Revenue / Company Size. What is the lowest cost threshold that a client would have to pay for your product or service?
  • Industry. Do you work within any particular industry verticals? With what verticals do you not work?
  • Legality. Are there any legal barriers to your potential client base, such as age, location, or government regulations?
  • Geography. Do you sell your product to a certain geographical area?
  • Prejudice and fears. What are your potential clients afraid of and what are they wary of?
  • Customer pain points. What problem do your clients want to solve and how can you help them with this? Or if clients are already solving their pain problem, find out how? Often people do the work that your product can do more quickly. It is very inconvenient and time-consuming.
  • Competitors. What competitors is your potential client using? What do your competitors have that you don’t?
  • Limitations in Product or Service. Do you have a service level agreement (SLA) with your clients that requires you to meet a particular response time? Can you ensure you’ll be able to make a schedule if someone requires a quicker response?

#4 Functional And Features

Based on the analysis that we described in the first part of our guide, you should describe your product’s functionality and work principle. This is a more technical part, but for design specifications, it is also necessary. Think about which features should be developed initially and which can be postponed for later. Think about the features you need to test and so on. 

#5 Aesthetics 

This part is one of the most interesting and enjoyable. Describe the visual concept of the product. Name the colors you want to see in it, style, interface features, and so on. Visual design is half the success of a product since people often give the first assessment based on visual perception. The most important thing is to explain your point of view. In our experience, conflicts may arise due to misunderstandings.

#6 Performance (where the product will be used)

Describe where your product will be used, in what areas it will be most useful, and what results it can bring to individual companies and users. Be sure to explain based on what you made such conclusions, whether you conducted any research or is it just your hypotheses. Also, don’t forget to research what users use most often. Do they use the product more from a mobile or computer?

#7 Add non-functional details

Non-functional details include the following things:

  • Usability. This focuses on how users interact with the user interface and how it looks. What is the color of the screens? What is the size of the buttons?
  • Availability / Reliability What are the requirements for uptime? Is it required to run 24 hours a day, seven days a week?
  • Scalability. Will the product be able to cope as demands increase? This includes spare hardware or space to install it in the future for physical installations.
  • Performance. How quickly does it have to work?
  • Supportability. Is support given in-house, or do you need remote access to external resources?
  • Security. What are the security needs, both physically and cyber-wise, for the installation?

#8 Add your recommendation and prohibitions

We recommend you draw up a table with your recommendations and wishes, describe them clearly and explain your point of view. Also, add prohibitions if you know for sure that you absolutely do not want to see something in your product.

#9 Add your questions

List the questions that you would like to discuss at some stage of product design and development. Write as much as possible. This will help you solve all possible problems and fix all possible mistakes.

#10 Design Specification: Summary

The most important thing to remember when writing a design specification document is that you are the only person who can fully represent your future product. Try to describe all the points in a detailed and clear way so that your team can easily bring your product idea to life.

Need help with writing a perfect design specification?

Northell team has a wealth of experience in writing such documents, so you can fully rely on us.

How to check my Design Specification?

You wrote the design specifications. All is ready. It’s time to check how well you did the task. Check your finished document with the points below.

The document is written as an instruction

Your design specification document should be detailed but without unnecessary repetitive information. Try to write it in the style of the instruction. It will be easier for designers to go through clearly written paragraphs rather than reading a lot of solid text. Highlight every important point and remember to follow the structure.

Based on facts and numbers

Support each of your thoughts with facts or numbers. This will give confidence to your design specification document. Don’t try to prove yourself right by just writing a few sentences about why you think so and not otherwise. Prove it with numbers, facts, trusted sources, and so on.

Strong business component

Your design specification document should be a strong business component. Otherwise, the process of creating a product will be disorganized. You risk missing important points and making gross mistakes. Your project must have a reasonable and correct monetization. If you start with MVP, think about which functionality will be the best and most accurate.

Clear requirements for contractors 

We have said more than once that your design specification document should be clearly described. Requirements for contractors should be no less clear. This is a critical stage that will help avoid future misunderstandings and conflicts. In order for the result to meet expectations, the basic requirements must be recorded in the document.

Without big ”black” holes

Check your design specification document several times to ensure there are no open-ended questions or poorly described parts. Remember that the success of your future product largely depends on this document, so you need to take it seriously.

Share document with your partner

Share the finished document with your partner and team. Make sure they understand everything and have no questions. Discuss each part of the document and if any questions arise, resolve them immediately.


Non-disclosure agreements are a legal framework that protects sensitive and secret information from being made public by the person who receives it. Companies and startups use these documents to ensure that their good ideas are not stolen by the people they are negotiating with. When creating and sharing a design specification document, don’t forget to use NDA.

According to Forbes, NDAs might also give you insight into the company’s attitude toward its employees.

Design Specification Example (Based on Northell Experience)

To make it easier for you in the future to draw up a design specification document, we have prepared a design specification example for you. We recently completed the Referrizer project. Referrizer is a marketing automation platform that helps get new customers, increase repeating purchases and generate long-term sustainable results.

Our client needed someone who will always cooperate with them to improve UX and platform in general. Before starting working on the platform, we have studied in detail the design specification document that Referrizer has prepared for us. 

So, here is the Referrizer design specification example:

  1. Full project overview. Referrizer is a marketing automation platform that helps get new customers, increase repeating purchases and generate long-term sustainable results. This communication platform increases referrals, boosts retention and improves the company’s Google reputation. Referrizer needs someone who will always cooperate with them to improve UX and platform in general. The first thing they need is the formation of a digital strategy.
  2. Main goal. The main goal is to become an industry leader and increase the number of companies using the platform. We are not allowed to give specific figures (NDA).
  3. Target client. Referrizer’s primary target audience is the owners of local businesses and their employees. The Referrizer also plans to release a platform targeted at restaurant business owners.
  4. Functional and Features. Referrizer needs a high-quality reputation management module, which will consist of four blocks: Dashboard, Review booster, Reviews management, Review widget. Referrizer also needs a responsive design for this module. 
  5. Aesthetics. Referrizer platform should be attractive to users. It is advisable to use colors such as white, blue, light blue. Referrizer also wants pages to have visual accents and the user’s attention to be drawn to the necessary blocks.
  6. Performance. Referrizer platform will be used in local businesses and by owners, managers and all employees of such companies. 
  7. Non-functional details. Referrizer platform should have high security and scalability, be available 24/7, be user-friendly.
  8. Questions. What tech stack do you recommend us to use during development? What are the best colors for the reputation management module? How big should the buttons be under the main blocks?

Design Specification: Top mistakes

The following is a list of the most common problems in writing design specs:

  • Making incorrect assumptions.
  • Instead of specifications (WHAT), writing implementation (HOW).
  • Instead of describing specifications, describing operations.
  • Using the wrong terms.
  • Missing specifications.
  • Over-specifying. 

Try to avoid these basic mistakes and you will be able to write a quality design specification document.


Writing design specs can be a powerful tool for ensuring the success of your project. A little thinking and planning can make the actual implementation of a project a lot easier. The guide we wrote above will help you master the basic skills of writing a design specification document. 

If you need to draw up a document quickly and in quality, please contact us!

We Are The Top 20 Product Designers & Developers on Clutch. We will gladly help you and guide you in the right direction!


How to write a design specification?

In the design specification document, you should include the following points:

-full description of your project
-business goals
-description of your target audience
-visual preferences
-color palette and general style requirements
-requirements for non-functional elements
-recommendations and prohibitions

We recommend describing each point in detail but clearly. If you include all the points from this list, your design specification document will be a great asset to your team.

What characteristics distinguish a good design specification?

A good design specification should incorporate information from your study on the task/problem. It is a collection of criteria that your design concepts should fulfill, as well as a list of restrictions. It is the checklist that you should employ while developing your design concepts.

Why is design specification so important?

The specification specifies the project's goal, functionality, and design. It may be used to refer to the quality and standards that should be followed. Materials and products from companies may be precisely specified. It is possible to identify setup, testing, and transfer needs.

What is the technical design specification?

A technical specification is a thorough document outlining all technical product development methods. It provides all of the essential details concerning the product development process.

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