When you launch a new product, your vision for its use might differ from how customers actually use it.

Marc Chavannes and Alfred Fielding, who invented bubble wrap, didn’t have packaging and shipping in mind when they sealed two shower curtains together, trapping air between. They tried to sell it as wallpaper. In other words, they probably didn’t foresee this use case—a product development process that helps identify target audiences and specify your product’s value.

What is a use case?

A use case describes how a person uses a system to accomplish a task. Use cases are most valuable in the very early stages of a project. If you map out how people will use a product, teams can figure out what they need to build.

A comprehensive use case will identify:

• An actor. The user.
• A product. The system being used.
• An action. What is happening.
• A goal. The desired result.

Ivar Jacobson created the first use case model in 1987 while working at Ericsson. It started as a tool for developing complex telecommunications systems. It evolved into a standard part of software design, specifically within the Unified Modeling Language (UML), a standardized visual language for describing complex systems.

Now, many industries create use cases to identify key audiences and develop products for them. For example, say you’re developing a new coffee maker. 

To justify investing in the product concept, your team defines a few key components:

• Actor. The busy morning commuter.
• Product. The Smart Coffee Maker.
• Action. The user sets a timer on the machine (or via an app) the night before to start brewing at 6 a.m.
• Goal. To have hot, fresh coffee waiting immediately upon waking up, saving time in the morning.

At the end of the day, a clear use case description gives your product development team a tool for solving customers’ problems.

How use cases work in software development 

In the tech world, a use case documents the steps a user takes to reach a specific goal. However, users don’t always follow a straight line. That is why a single use case usually contains a few different scenarios.

You can typically break use case scenarios into three types:

• The basic flow. Also called “the happy path,” this is the ideal scenario. Everything goes perfectly, and the user reaches their goal without issues.
• Alternative flows. These scenarios map the various paths a user might take to reach the same goal, like clicking a different button or using a shortcut.
• Failure scenarios. These describe what happens when a product or user error occurs.

Using a banking login as an example, here is how the different flows could work:

• The basic flow. The user enters their username and password correctly and logs in.
• The alternative flow. The user logs in using a fingerprint scanner or facial ID instead of typing a password.
• The failure flow. The user enters an incorrect password three times. The system spots the error and locks the account to keep it safe. 

Identifying failure flows during product research and development gives developers a chance to implement a solution before launch, such as creating a feature that allows users to reset their passwords securely.

How use cases work in other industries

In contrast with software development, use cases for physical products focus less on pinpointing errors and more on understanding and connecting with the target audience.

Developers and marketers of physical products create use cases to identify problems their product will solve for different users. A use case for a new fridge might focus on an ergonomic handle that’s comfortable for people with arthritis. To build it, developers would ask people with arthritis to test the handle to ensure it meets their needs. Marketing materials could then use language and imagery appealing to this audience.

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What is a use case diagram?

A use case diagram is a visual representation written in UML. It demonstrates how users interact with a system to achieve their goals, and shows what the system does simply—in other words, without getting lost in the technical coding.

Diagrams provide clarity for teams. Research from the Project Management Institute found that global teams using its Net Project Success Score rated less than half of their projects as successful. Using visuals to identify missing product features and align on scope early improves your chances of landing in the success group. 

In 2025, Canva reported that design-led companies, or businesses that prioritize visual communication, report more efficient communication, brand cohesion, and brand differentiation than text-first companies.

To read a use case diagram, you only need to know a few symbols:

• Actors. Stick figures representing people or external systems.
• Use cases. Ovals labeled with specific goals.
• System boundary. A box around the use cases showing what is being built versus what is external.
• Associations. Lines connecting actors to the goals they perform.
• Relationships. Dashed lines show connections between goals. Use «include» for mandatory steps and «extend» for optional ones.

A diagram supports your written use case. It’s like a map that shows the layout, while your text-based version provides turn-by-turn directions. Using both ensures your team agrees on who’s doing what before they start building. 

Use case vs. user story vs. test case

While these product development terms are often used together, they serve different purposes.

Use case

• What it is: A structured description of how an actor interacts with a system to achieve a specific goal. It focuses on system behavior, scope, and flows.
• When to use it: Best for complex systems or regulatory industries. It shows detailed flows and interactions to ensure team alignment on what to build.

User story

• What it is: A short, value-focused requirement used in agile design. It follows the format “As a [who], I want [what], so that [why].”
• When to use it: Best for iterative delivery and prioritizing customer value. It’s not a complete set of instructions, but more like a sticky note to discuss when creating your use case. 

Test case 

• What it is. A set of inputs, steps, and expected results created to verify that a specific requirement works correctly.
• When to use it. Best for QA and regression safety. It provides evidence that the software or product complies with requirements.

Use cases, user stories, and test cases are tools you can use in tandem. Pair user stories with use case sketches to clarify complex interactions. Then create test cases based on your findings to ensure the product actually meets its goal. 

Types of use cases

Business use cases

A business use case outlines the big picture. It describes how a process will provide value. It doesn’t account for the specific software involved; instead, it focuses on business results and interdepartmental collaboration.

💡Example: An end-to-end ordering process tracks a purchase from the moment a customer places an order through the sales process, inventory check, warehouse fulfillment, and final shipping. It demonstrates how real-world operations across teams deliver value to the customer.

System use cases

A system use case explains how a software application supports a user’s goal. It defines inputs, data validation, and error messages within a system boundary. 

💡Example: In an order management system (OMS) use case, a user enters order details. The system then validates the input, queries the database, calculates the total, saves the order record, and finally displays a confirmation to complete the specific task.

Benefits of use cases

• Home in on the product’s value
• Prioritize key features
• Gain marketing insights
• Strengthen product alignment

A good use case can help you do the following:

Home in on the product’s value

A use case illustrates your product’s value by outlining exactly how it helps your target audience achieve their goals. Although you don’t share use cases with customers, they do inform your unique value proposition and marketing materials.

Exploring different use cases for your product strategy can reveal new, unexpected values and audiences. For example, a desktop mini fridge initially intended for beverages might also appeal to customers needing refrigeration for skin care products. In tech, these alternative scenarios describe situations where consumers “misuse” software—or use it in unexpected ways. 

Prioritize key features

Understanding how your audience uses your product helps you identify and prioritize essential features or benefits. It can also help with project planning and budgeting by focusing resources on the most critical features.

The key benefits you identify also serve as the basis for test cases that validate the efficacy of your product’s features. For example, if the key benefit is speed, you could prioritize a one-click checkout feature. The test case would verify that a user can complete a purchase in less than five seconds without re-entering their shipping information.

Gain marketing insights

Product marketing relies on use cases to convey a product’s value to various audiences. Tailoring the language in marketing materials to the target audience and their specific use of the product ensures it resonates.

Aligning your messaging with your audience’s perceptions of their challenges or problems can make it easier for them to see your product as a solution.

Strengthen product alignment

A use case is a compass for your product team. When you define user goals and system limits upfront, you prevent scope creep. This clarity helps designers base the user experience (UX) on real needs rather than assumptions.

Since designers and developers share a concrete plan, they avoid messy handoffs and confusion. Everyone understands exactly what to build, so the solution matches the problem.

How to write a use case for a product

1. Select a user
2. Describe the user’s goal
3. Show how the product helps achieve this goal
4. Identify key takeaways
5. Repeat

In retail, a use case typically describes how a hypothetical customer interacts with and benefits from your product. You may need several use cases to cover various customer interactions. This use case template can help you write your first one quickly, and serve as a framework for your second (and hundredth) use case, too.

1. Select a user

Write a brief description of a hypothetical user from your target audience by asking, “Who is this product for?” Then create a use case for each user you identify. 

A user, or actor, can be anyone or anything who interacts with your system—an employee, a customer, or a software system that interacts with the product. 

For example, if your product is a collapsible bike helmet, the actor might be an urban professional who rides their bike to a coworking space.

2. Describe the user’s goal

Once you’ve chosen a user, describe their goal or pain point related to your product. Focus on the user’s perspective, incorporating insights from customer feedback, surveys, or social listening. Capture how the user actually perceives their goal or pain point, not how you hope they see it.

For the commuter cyclist, the pain point is a clunky helmet that doesn’t fit in a bag. They want to stay safe, but they also need convenience when meeting friends after work. In this case, the preconditions might be:

• The user has arrived at their destination
• The helmet is currently fully expanded and latched

3. Show how the product helps achieve this goal

Explain exactly how the user interacts with your product to solve their problem. Outline the steps they take.

Start with the basic flow, or the ideal scenario. For the commuter cyclist, this looks like:

• Arrive at the coworking space
• Collapse the helmet
• Slide it into the backpack

Next, consider alternative flows where the situation changes. For instance, what if the user stops for groceries and their backpack is now full? They can no longer put the helmet inside.

Mapping these different paths highlights necessary design improvements. If you identify the full-bag scenario early, you might decide to add a carabiner clip to the helmet so the user can attach it to the outside of their bag.

4. Identify key takeaways

A use case isn’t something you write once and never look at again. After you’ve used it to develop a product’s functional requirements, it can serve your marketing efforts.

For instance, key takeaways from the commuter cyclist use case include the need for a helmet that fits in a messenger bag, work tote, or backpack. Since users frequently collapse and unfold the helmet, switching between storage and biking modes must be quick and easy. You can demonstrate this to potential customers in video ads on social media.

📖Read more: Types of Advertising: 14 Ways to Market a Product

5. Repeat

Repeat this process for each target audience. Then, compile your product’s use cases into a single document to reference for promotional campaigns.

Product use case example

Most products have a variety of use cases. Consider the Slick Salve lip balm from skin care company Topicals. According to product marketing lead Roxana Ontiveros, her company developed the balm with multiple use cases in mind.

“It’s not only for a person who has existing dryness, but it’s also for people who are on Accutane,” she says. “And then it’s also a good use case for someone who maybe wants a cosmetic benefit. So they want something that’s kind of slick, kind of glossy.”

Even the name Slick Salve captures these different use cases: “Slick” describes the cosmetic appeal of glossy lips, while “salve” conveys its healing properties. For Roxana, use cases serve her goal of reaching as many audiences as possible while remaining specific in product storytelling and messaging.

You can apply the same frameworks mentioned above to the Slick Salve lip balm. For example, say the user has a medical need:

• Actor. A customer using strong acne medication (Accutane).
• Goal. To prevent painful cracking and soothe extreme dryness.
• Preconditions. The user’s lips are dry, tight, or peeling due to medication side effects.

Basic flow:

• The user feels irritation or tightness.
• The user applies a thick layer of the balm.
• The formula seals in moisture.

Postconditions: 

• The user feels immediate relief, and a protective barrier is formed.

This article originally appeared on Shopify and is available here for further discovery.