Once you understand what errors occur, you can analyse how they have happened in order to focus your activity and reduce the risk of them happening again. A method of doing this that was originally developed for use in the automotive and motor industries is known as Failure Modes Effects Analysis (FMEA).

FMEA analyses errors in two ways: the magnitude of the risk and the cause of the error.

The magnitude of the risk is based on the likelihood of the error occurring and the seriousness of the potential consequences. This allows us to decide what actions need to be taken.

For example, in the automotive industry, a potential fault with an interior light that occurs in every fourth car may warrant no further action than simply waiting for owners to visit a dealer for a regular service. If the fault was with the brake system and caused a catastrophic brake failure in one in 100,000 cars, this might warrant the recall of all of the cars so they could all be tested for the fault.

Events are then described as violations or errors.

A violation occurs when someone chooses to deviate from an agreed process. This should be dealt with as an employment disciplinary issue. An example might be a dispenser who assembles and hands out a prescription without it being clinically or accuracy checked.

Errors are subdivided into skill-based, rule-based or knowledge-based:

Skill-based errors are further subdivided into slips and lapses. A slip occurs when someone is trying hard and is focused but still ends up making a mistake. This could include products that sound alike (e.g. penicillin and penicillamine) or products that look alike (e.g. different strengths of the same drug from one manufacturer). Lapses are errors that occur when someone has lost concentration and is distracted.

Rule-based errors are those where the person thinks they are following the process but makes a mistake. This might be due to an SOP that is misunderstood or a failure in the process that has become a bad habit. An example of this for many of us is driving. While we will have been competent drivers and followed the rules of the road accurately when we passed our driving tests, how many of us have lapsed into bad habits without realising it?

Knowledge-based errors are errors that occur because a team member has not been trained sufficiently or has too little experience to accept the level of responsibility given to them. An example of this might be inexperienced counter staff putting away stock in the dispensary, which could lead to misplaced stock being picked incorrectly by dispensing staff.

Analysing these errors in this way will allow you to understand why they happened. This, in turn, will allow you to plan appropriate measures to reduce the risk of them happening again.

Factors that lead to errors

Errors often occur when a person’s ability to concentrate and focus has been diminished. This can be due to distractions or stress.

Stress is a major factor that leads to broken concentration. Too much stress from overwork and staff shortages can lead to errors occurring. However, too little stress can also lead to increased errors.

In fact, research has shown that there is an increased error rate in pharmacies that are quiet compared with those that are busy. This is due to the concept of working in the performance zone; we need a certain amount of stress to perform effectively.

This concept also explains some of the reasons for the timing of errors. Many errors occur very soon after lunch or a break. The level of stress at this point has not driven people into that performance zone that will improve focus. Circadian rhythm also contributes to the timing of errors. Circadian rhythm is the natural body rhythm that is driven by changes to hormone levels.

These changes lead to differences in our abilities throughout the day. Generally, most people have best concentration before noon, so the working patterns we adopt should reflect this. Perhaps it would be better to check MDS (monitored dosage system) dispensing in the morning, while it would be better to dispense into MDS formats in the afternoon.