Task Success Rate (TSR) is a key performance metric used to evaluate the effectiveness of a certain process by tracking how successful individuals are at completing a certain task.

TSR formula, Reference values and Examples

TSR = (Number of correctly completed tasks / Total number of attempts) × 100

Reference values:

  • 80–90% = Generally good experience
  • Below 70% = Indicates usability issues

TSR in different scenarios:

E-commerce checkout

  • Task completion criteria: completing a purchase
  • Measure: % of users who successfully complete checkout
Example of TSR for eCommerce store tasks. Image by Nick Babich.

Booking appointment

  • Task completion criteria: Successfully submitting a form
  • Measure: % of users who submit without errors

Help center usage

  • Task completion criteria: Finding the correct help article
  • Measure: % of users who solve their issue using the knowledge base

Key Considerations for Measuring TSR

Before measuring TSR, you need to specify clear criteria for task completion. Success can be measured in different ways, such as

  • Binary success/failure: Did the user complete the task correctly? (Yes/No). Binary success/failure works well for tasks like eCommerce checkout when we evaluate success by measuring a conversion rate.
  • Partial success: Did the user complete part of the task correctly? Partial success works well for tasks like Help Center usage when we cannot be 100% sure that the information the user finds solves the user’s problem.

How to collect data for TSR

There are multiple ways to gather data on task success.

Usability testing

Usability testing (moderated or unmoderated) is by far the most common way of collecting TSR. You can observe real users attempting tasks, record whether they complete tasks successfully, and note any challenges they face along the way. Notes you collect while observing users can provide additional valuable insights that will help you reveal underlying issues in the user journey.

Analytics & clickstream data

You can use analytics tools like HotJar or FullStory to track how users interact with a digital product. You can specify a certain goal (such as submitting a form or making a purchase) and identify if your users reach the intended goal. The downside of this approach is that you have limited information about what prevents users from achieving the goals. So, it is recommended that analytics be used with other methods.

Surveys

In some cases, it’s possible to ask users directly if they were able to complete the task. For example, you can ask, “Were you able to complete your task successfully?” (Yes/No)

How to improve TSR

Many times, TSR is directly tied to the usability of your product.

The better the usability is, the higher the TSR will be

If TSR is low, consider reviewing user flow and optimizing it:

  • Reduce unnecessary steps;
  • Improving navigation and layout;
  • Use auto-fill and defaults (pre-populate fields where possible);
  • Providing better guidance (tooltips, help text). You can use progress indicators like steppers to show users how far they are in multi-step processes;
  • Design better error states (refine error messages and offer better recovery options);
  • Conducting more usability testing and iterating. Compare different versions of a flow to see what improves TSR.

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Task success rate: Essentials was originally published in UX Planet on Medium, where people are continuing the conversation by highlighting and responding to this story.