Identifying and Removing Sludge

Sludge is any friction or hassle that makes a process needlessly difficult, like a rebate form that requires mailing in three different proofs of purchase. The first step to removing it is to map the process from start to finish, which means listing every single action the user must take. This visual map reveals exactly where the frustrating, time-consuming, or confusing steps—the sludge—are located. By seeing the whole journey, you can pinpoint the obstacles that cause people to get stuck or give up entirely.

Ask this: What is every single action a user must take to complete this task, and why is each one there?

Identifying and removing sludge is a systematic process, often called a "sludge audit," used to eliminate unnecessary friction from systems. The process begins by mapping the user journey to document every step a person actually takes to complete a task, not just the official procedure.

With the journey mapped, the next step is to analyze it for friction points. For each step, ask if it is essential, confusing, or causes delays. These burdensome steps are the sludge that needs to be addressed.

Once identified, quantify the sludge's impact. The costs can include wasted hours for customers and employees, high abandonment rates on applications, or direct financial losses that demonstrate the need for a redesign.

Finally, brainstorm and test solutions to eliminate the sludge. For example, a university simplifying its financial aid application sees higher completion rates, improving equity. A company that automates IT onboarding reduces employee frustration and cuts administrative costs. A hospital that digitizes redundant discharge forms saves staff time and improves the patient experience.

Behavioral science frames sludge as a tax on cognitive resources, time, and well-being. It goes beyond mere inconvenience to create significant barriers that can prevent access to essential services and benefits. A sludge audit is the diagnostic tool used to identify and measure these friction costs before they can be removed through process redesign.

• Cass Sunstein, who popularized the term, defines sludge as excessive or unjustified friction, whether intentional or not, that imposes cognitive, emotional, and financial costs on individuals trying to navigate a process. [1] (2021)
• Research on "administrative burden" by Pamela Herd and Donald Moynihan shows how sludge in government programs, such as complex application forms for food assistance or healthcare, prevents millions of eligible citizens from receiving benefits they are entitled to. [2] (2018)
• A field experiment by Hallsworth et al. demonstrated that simplifying tax letters by removing sludge (e.g., using clearer language, highlighting key information) significantly increased the rate of on-time tax payments, providing clear evidence for the economic benefits of sludge reduction. [3] (2017)

Not all friction is bad. Some "sludge" is necessary for security, safety, or to encourage deliberation. For instance, a waiting period before closing an account can prevent rash decisions, and two-factor authentication adds a protective barrier against fraud. The key is distinguishing necessary friction from unnecessary sludge. Furthermore, removing sludge can be costly and complex, especially in large, legacy systems, and the benefits might not always justify the resource investment required for a complete overhaul.