Common Mistakes in Food Safety Root Cause Analysis

Food facilities have a variety of mechanisms for identifying food safety failures, including customer complaints, self-inspections, audits, and regulatory visits. The key to success is being able to take action to prevent recurrence of these failures, or at least reduce its likelihood, by identifying and addressing the root cause. There are several tools available to facilitate root cause analysis, such as Five-Whys, Fishbone Diagrams, and Pareto Charts, each of which is designed to facilitate a thorough investigation. Following are three of the most common mistakes made in root cause analysis:


Let’s use the analogy of a patient visiting a doctor to understand how we must look past the “symptom”. The patient may present with several different symptoms such as headache, fever, and sore throat. The doctor does not treat each symptom with a different medicine, but asks, “Why is the system sick?” then seeks to find the root cause and treat that issue.

The same sort of approach should be taken when seeking to address a variety of food safety issues in a facility. For example, there may be several findings from a self-inspection that seem unrelated: e.g., improperly re-assembled equipment causing metal contamination; drain fly activity around waste material left in the production area; hold-area materials not clearly identified.

While each of these may seem like a different issue, a thorough investigation may find that they all have the same root cause: responsibilities were not clearly defined. In this example reassembly of equipment should have been done by maintenance, but sanitation was doing it; production personnel should have been removing waste containers at the end of their shift, but they left it for sanitation; production workers who moved the materials to the hold area should have identified the product, but they assumed quality would. By ensuring that the root cause, not just the previously surfaced symptoms, is addressed, future similar issues can be prevented.


We often hear the phrase, “perfect storm” after a failure. Rarely is the root cause a singular item or issue. Think of a decomposing rodent found in a trap in a warehouse. Upon investigation, we find that there were several contributing factors:

• The site next to the facility was an open field, but recently, construction began on the site, driving rodents toward the food facility.

• The food facility was having a new line installed, so there were contractors onsite, many of whom propped doors open to ease their movement from the installation area to their trucks.

• The facility made a significant change to its packaging, so the warehouse was overstuffed with obsolete packaging waiting for disposition. This caused the trap to be inaccessible during several scheduled device inspections.

If any one of these had not occurred, we likely would not have had the decomposing rodent.


One of the most common preventive measures that tends to be identified for food safety deficiencies is “retraining,” which puts the blame on people rather than the system. It is the food facility manager’s job to ask, “How do we make it easy for our employees to succeed and hard for them to fail?” Following are some examples of issues that you may be tempted to treat with retraining, but that have better solutions that take the responsibility off the individual:

A pedestrian door in the warehouse is left ajar, allowing pest ingress. Rather than simply retraining employees to keep doors closed, install self-closing devices (springs) on the door.

Materials rejected by the metal detector are put back on the line without evaluation. You could train personnel to leave materials rejected by the metal detector for the QA team, but it’s better to install a locked container to capture rejected materials, and ensure only authorized personnel have access.

Untrained employees cleaned line 4 conveyors with a chemical that is not approved for food-contact surfaces. Tell personnel to only use chemicals on which they have been trained, but also install a locked cage for chemicals accessible only by authorized persons.

Keep in mind that training may be a contributing factor. However, rarely is the solution to retrain an employee or set of employees. Rather, the solution is to redesign the training approach. I invite you to share these common mistakes with your management team and any others involved in resolving food safety issues within your organization. As you conduct your investigations to identify root cause and prevent recurrence, keep these “watch outs” in mind to improve your rate of success.