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Staff & Training

Guest Blog Post: Getting a Straight-line Shift through Human Factors with Tim Rice

Ryan Chan

Tim Rice is a Principal Consultant at The Defect Elimination Project and holds over 15 years of experience in the mining and resource industry.

He provides expertise in the areas of asset management, risk identification and mitigation, and life cycle management.

Straight-line shift theory is a visual way for maintenance professionals to determine how a plan was executed against how it was intended to be executed.

In this article, I will cover:

  • What is straight-line theory shift?
  • The 12 human factors that lead to maintenance mistakes
  • Human factors vs. human errors
  • Getting started with a straight-line shift
  • The varying nature of human factors

What is straight-line shift theory?

Straight-line shift theory is used to compare how a plan was executed against how it was intended to be executed. It is also then used to identify and eliminate the deviations that occur between planning and reality.

Imagine a straight line on a piece of paper is your plan for the shift – with no bumps or blips along the way. Now as you work through the day you draw a line that represents how your shift actually went – including any deviations against the original straight-line plan. How much did your “actual” line deviate from the straight “planned” line?

The aim of a straight-line shift

The aim of a straight-line shift is to get the actual line as close to the straight planned line as possible. Any deviations from the planned line indicate some kind of value was lost during the shift, whether it be a monetary value or emotional value. In the world of Defect Elimination, all of these deviations are considered defects because they are eroding value from the business and a similar process can be used to eliminate them.

To eliminate these deviations you first need to identify and understand what the deviations are. For example, there could be the need to go look for parts (or the correct parts), to look for tools that are needed to complete the job, or there are delays, due to people being taken off of one job to work on another.

Keep in mind though that there can be times where your actual line is above the planned line, meaning you finished ahead of schedule. This can be a good result and indicates that everything went better than planned but may also indicate problems with the original plan or the execution of it. For example, a task that was planned for 4 hours only took 3 hours because there was a perception from the maintenance crew that they were under pressure to get the job done as quickly as possible, and to achieve this they skipped some of the steps in the maintenance procedure.

12 human factors that lead to maintenance mistakes

The root cause of most deviations, if not all, will generally fall into one of the human factor categories that were developed by Transport Canada and later adopted by the Federal Aviation Administration (FAA).

The FAA states that 80% of maintenance mistakes come from human factors.

They believe these human factors lead to mistakes that if not identified and prevented, would negatively impact the aviation industry and those that use it. The twelve human factors as defined by Transport Canada and the FAA are:

1. Lack of Communication

The failure to transmit, receive, or provide enough information to complete a task.

2. Complacency

Overconfidence from repeated experience from performing a task.

3. Lack of Knowledge

A shortage of the training, information, and/or ability necessary to successfully perform a task.

4. Distractions

Anything that draws your attention away from the task at hand.

5. Lack of Teamwork

The failure to work together to complete a shared goal.

6. Fatigue

Physical or mental exhaustion threatening the ability to correctly execute the task at hand.

7. Lack of Resources

Not having enough people, equipment, documentation, time, parts, et., to complete the task at hand.

8. Pressure

Real or perceived forces demanding high-level job performance.

9. Lack of Assertiveness

Failure to speak up or document concerns about instructions, orders, or the actions of others.

10. Stress

A physical, chemical, or emotional factor that causes physical or mental tension.

11. Lack of Awareness

Failure to recognize a situation, understand what it is, and predict the possible results.

12. Norms

Expected, yet unwritten rules of behavior.

Human factors vs. human errors

When getting down to the human factor level it is important to understand that these are not the same as human errors. What often happens in a root cause analysis (RCA) is that we stop at the human error level which is only a symptom of the root cause and can also come with the stigma of blame. A human error is where an individual or a team does or does not do something. The human factor identifies why the individual or team did or did not do something. For example, an individual did not correctly torque down the bolts on a pipe flange (the error) because they did not have a torque wrench available (human factor – lack of resources).

Most often when the deviation is identified they are only at the human error level (or symptom level), so every effort must be made to get down to the human factor level.

Getting started with a straight-line shift

Alaska Native worker at Pebble copper gold mine project Bristol Bay

To start your journey to a straight-line shift by using the human factors you need to do the following.

1. Create an open dialogue loop

At the end of the shift, each person can voice what caused them to deviate from the plan and which human factor(s) this aligns with. The team can then decide on the action needed to remove it.

2. Record the human factors

Take note of the human factors and actions against the corresponding work order, so there is a record of what needs following up and why. Over a period of shifts you may start to find similarities in what the deviations and their corresponding human factors are. This might be in a spreadsheet, or on a whiteboard where the straight-line shift is discussed each day. If the spreadsheet method is used it is a good idea to print it out so the workforce can see the progress.

3. Address the human factors

The human factor(s) for each work order then needs to be addressed, so that the next time the work order comes out, the human factor(s) are eliminated; or, at the very least, action is in progress. Communicating any progress will improve engagement in this process.

4. Keep score

Keep a score of what human factors have been eliminated and what the improvement was.

5. Document metrics that show improvement

If there are metrics that can be linked to measure the improvement seen by using straight-line shift theory, then post them. Improvements may range from a decrease in rework, to improve asset availability, to increasing PM compliance. While these are considered quantitative measures, you can look to measure how straight-line shift is impacting people emotionally by getting their feedback.

To understand how well straight-line shift is reaching the workforce and making an impact on emotional value, you might want to ask some of these questions and have the workforce give you a ranking from 0 to 10. Of course, this can be anonymous and done at intervals of every month or more to gauge if this is making a positive change.

* Emotional Value: A set of positive feelings such as being happy and feeling good.

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Yes – Always

1. Do you understand what SLS is and what it is aiming to achieve?

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2. Do you trust your leaders to do what they say they are going to do in the SLS program?

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3. Are you actively involved in the SLS process?

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4. Are you getting what you want out of SLS?

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5. Is SLS something you think about during your day?

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The varying nature of human factors

You also need to understand that there will be times where you may think you have eliminated all of the human factors; however, as circumstances change within the business or with the workforce, so might the human factors. For example, a significant drop in commodity prices might be drastic enough that the company is looking to lay some of the workforce off. This is a big distraction which draws attention away from the tasks assigned to the workforce and may also result in emotional stress for fear of not being able to provide for their family.

Human factors can be broad

Human factors can be very specific to certain individuals. For example, a lack of knowledge may apply to only some of the workforce as they are new and have not yet gained the necessary experience or training to successfully perform a specific task.

Human factors can be sensitive

Similarly there may be times where some people are embarrassed to bring up human factors related to their role competency. For example, Jim knows that he has a lack of knowledge in a certain area despite completing the same training as everyone else, but is afraid to bring this up as it may look as though he didn’t pay attention in the training class.

Human factors aren’t always clear

There can also be situations where someone else has seen a human factor in an individual that they haven’t yet noticed themselves. For example, Susan notices that John isn’t performing some of the inspection tasks on a boiler as thoroughly as required. The inspection tasks have never revealed any faults before, and because of this John has grown complacent when performing them.

Human factors can be personal

Some human factors can also be very personal, like those related to fatigue and stress, so those experiencing these may not be comfortable bringing them up in an open forum. There needs to be a process where these can be discussed one-on-one and managed with discretion.

Conclusion

Now that we know the basics about what a straight-line shift is, how to manage the process by linking the deviations to human factors, and finally eliminating them, could this be something that would improve efficiency and effectiveness while also making a positive cultural change by removing the everyday barriers that impact the workforce and ultimately improve the overall business?


More resources

Want to learn more about defect elimination? Check out Tim Rice’s episode of Masterminds in Maintenance.

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