Human elements in work design and measurement

Work Measurement

The Dynamics of Work Design

Work is an economic activity for everyone involved. Managers wish to maximize their outputs, while minimizing their inputs. The worker has the same goals as the manager from this standpoint. They wish to perform their work in the most efficient manner possible so that they can realize the maximum rewards. The industrial revolution meant the interaction of humans and machines in an attempt to increase productivity. Machines can perform their tasks efficiently. However, there has not been a machine invented to date that can operate entirely without any interaction from human beings. Machines serve man, not the other way around. Therefore it is important for machines to be designed so that they meet the needs of their humans. The following will explore the human elements in work design.

Work Systems

Regardless of the technology involved every work environment represents a system. This system consists of many parts, all of which must function synchronously in order for the work to be accomplished. Every corporation is like an assembly line with different parts. All of the parts must work together to produce a product. This is easy to understand when one thinks of a manufacturer, such as an automobile manufacturer, or a computer manufacturer. However, other systems might not be so obvious such as a bank, or delivery service. These businesses still offer a product, even if that product is actually a service. In the case of a bank there are tellers, managers, people who service the ATM machines, and building maintenance people, all of whom work together to produce a product. This is an important concept to understand when one talks about job design and the human factor.

Work Measurement

Work measurement means knowing the time that a given task will take if it is performed by a qualified worker in a defined field of performance. This means that the time it takes a worker to perform a given task becomes a known rather than a variable. From an operations management perspective, this is important for many reasons. It allows them to schedule production, make more accurate estimates of costs, and estimate staffing levels. Work measurement is an important part of operations management.

There are many ways to measure tasks, all of which will be suitable in different circumstances. There are three basic stages to work measurement. There are other variations on the tasks, but all of them contain these three basic phases. The phases are analysis, measurement, and synthesis. When one begins to breaks a complex task into its elemental components, a complex process is no more difficult than a basic one (Reeder, 2005).

In the analysis phase the job is divided into its various components or elements. The same job can be divided in different ways, but the end result is the same (Garmire, 2002). For instance, a candy cane manufacturer may wish to analyze the packaging phase of the process. They would analyze each and every phase of the process. For instance, one person my load the machine, another may turn the packages a certain way, another may inspect packages and pull them off the line to be put into larger boxes for shipment. Let us examine the final phase of the packaging component of manufacture.

The last person actually performs several different tasks. They must visually inspect the packages to make certain that they meet certain criteria. They might make certain that all of the pieces are oriented correctly; the labels are on correctly, the package is intact and has no smudges, and that the correct label is on the correct product. This in itself is a complicated process. The beginning worker may have to go through the checklist on each and every package that comes off the line. The experiences worker has an image of the perfect product in their mind and just "knows" whether the product is correct or not. The experienced worker can perform this phase much more quickly and with fewer errors than the inexperienced worker.

This phase of the operation requires a decision: Is the product correct? If the product is correct, then the worker must pick up the package, make a 90 degree turn and place the package in a crate. If the package is incorrect, then they must toss it into a re-work bin located on the other side of the conveyor belt. There are several things that may go wrong at this junction, all of which add up to lost time and money from an operations management perspective. The first thing that can go wrong is that the worker may incorrectly identify an imperfect package. In this case a faulty product gets packaged and shipped to the customer. This could have dire consequences for the company depending on the severity of the fault. The worker could toss perfect product into the re-work bin, which costs time and money for the company. Both of these errors are important from an operations management perspective.

The decision is the first step in the process. Let us assume that the product is correct. The worker now has to pick up the package, turn their body 90 degrees to the right and place the package into a larger crate. They must orient the package correctly and make certain that they do not damage the package in the process. They must complete this process 20 times until the crate is filled. Now let us say that they must pull a lever located to the left to temporarily stop the machine so that they can tape the package and place it on another conveyor belt that goes to the shipping department.

Now the process gets complicated from a work design perspective. All of these operations could be performed by the same worker in multiple steps. Work could also be designed so that it takes more workers, each of which performs a smaller portion of the work. One worker may inspect the packages as they pass on a conveyor belt and only pull the defective ones off into a re-work bin. The perfect packages may then continue down the conveyor belt to a packer who pulls them off and places them into the crates correctly.

They may not stop the belt as in the previous scenario. There may be another person that must wait until the box is full and then pull it off for the person, putting another empty in its place. The packer in this case never has to stop the motion of pulling the packages off the line, turning 90 degrees and placing them in the crate. The puller may simply pull the packages off the line and place them on a conveyor for someone else to tape, or they may perform the taping themselves.

Now we can see how a job is broken into its various components and how these components fit together. Job design is not set in stone and there are many different ways to accomplish the same task. Typically, the faster the line, the more people are needed. However, each and every worker performs a smaller portion of the total process. On slower lines one person may in fact perform 3 or 4 steps of the manufacturing process. The example of the packer may apply to a candy cane maker, where the line churns out 100s of 1000s of pieces each day. By contrast, as welder who welds frames on an auto assembly line may perform 3-4 welds before sending the car down the line for the next step.

This brings us to the next phase of the work measurement process, measurement. This phase of the process refers to the actual establishment of the time requires to perform the task or series of tasks. One some lines the worker may not have a choice in the time that it takes to perform a task. Using the example of the candy cane manufacturer, the line moves at a certain rate of speed. The packer may have exactly 5 seconds to pick up the package, make the turn and place the package in the crate. If they take 7 seconds at any time, they miss the package and it may have to go on to a second packer who is simply there to catch the first persons' mistakes.

The person must perform the repetitive task thousands of times a day in exactly the same way. The worker has no control over the time that they must take to perform the task. Repetitive jobs such as these may produce fatigue which can increase the number of errors or may cause injury to the worker. This does not even take into consideration the mind numbing effect of the work. These factors are what are meant by the human factors in job design and measurement. Humans have physical needs that must be met from time to time. Technology can help us perform our jobs more efficiently, but humans are not machines and have needs that must be fulfilled, including social needs.

The worker on a fast line such as a candy cane maker has little control over their environment. They must perform more like machines themselves. The welder on an auto manufacturing line may have more control over their environment. For instance they may make the welds necessary and then press a button to send the car on down the line. They control how fast the line moves. However, it is much more important for the welds to be performed correctly. If an imperfect candy cane goes out, the consequences are less serious than if a car frame is welded incorrectly. This is the different amounts of control that a worker has in the speed of production.

More experienced welders would be able to make the welds faster than inexperienced welders. However, speed is not the most important element when welding automobile frames. They must be done right, even if a few seconds, or even minutes are sacrificed. Therefore, we can surmise that the amount of control a worker has over the speed of the tasks is directly related to the importance of quality over quantity. This is directly related to the consequences that the end consumer could face as a result of error.

The measurement phase means determining the average time that it takes a worker to complete a task. Line speeds are the result of work measurement. If a human cannot possibly perform a task in the required amount of time, then the production speed must be slowed so that it is possible to complete the task. There are many phases of the operation than can best be performed by robotics. For instance, if a package needs to be turned over at some point, a robot may be best suited for the task, rather than a person. Many packing tasks are performed by robots. Robots make measurement an easy task as they can perform the same task thousands of times in a row exactly the same way (Polakoff, 1990). They can often perform many steps of the work much faster than their human counterparts. They are not as prone to injury as humans either. The use of robotics is an important element of job design.

The efficiency of robotics and their ability to perform a task over and over in exactly the same way without complaint is a major consideration in using them in the manufacturing process. However, there are many things that a robot cannot do that only a human can do. For instance, a robot cannot make a decision as to what is a perfect package and what is not. The use of scanners is making this task easier. For instance, it is now possible for a robot to detect certain flaws in a package, but they still cannot replace the reasoning skills of a human being in many areas. Humans are necessary and machines cannot operate completely independent of their human counterparts at the current time. They can help with tasks that could cause injury to the worker, but they cannot make decisions the same as a human being (Vicente, 2002).

Job measurement is easier when it comes to machines performing the task than if humans perform it. However, it is not always possible for the machine to perform each and every task. Often the job is performed by a combination of machine and human elements, all of which must work together in perfect harmony (Vicente, 2002). Synthesis is the final phase of work measurement. This means putting all of the various elemental times together with appropriate allowances for the human factor. This results in a standard time to complete a job.

The Human Factor

Up until this point in the discussion, the work of the human and the work of the machine are performed in the same way. The human is treated as just another step in the production process. We mentioned the human factor as far as reliability is concerned and that human needs can reduce the reliability of the human, as compared to the machine that can perform the same task tirelessly day in and day out, as long they have proper lubrication to do so. However, humans need much more than a little machine oil from time to time.

Over the course of the working day the worker will experience fatigue. Adverse working conditions such as extreme heat, or fumes may increase the fatigue experienced by the worker. Operations managers must make an allowance for this to allow the worker to recover from the fatigue. The work and conditions determine the allowanced needed for the average worker to recover. Allowances cannot compensate for unsafe or unhealthy working conditions, and they must be sufficient to recover. There is often a trade-off between worker fatigue and maximum production efficiency. A worker that is fresh can perform the tasks more quickly and efficiently than a tired worker.

Anticipating worker fatigue, machine maintenance and times between machine failures are also allowances that must be made if one is to obtain the most reliable work measurement. Many of these factors can be estimated with a high degree of accuracy. Careful observation over time is the key to accurate work measurement. Each observation represents a data point. Just like any other scientific study, the more observations made, the more accurate and reliable the results. After a sufficient number of observations outliers can be easily identified. A greater number of observations mean more reliable estimations of work and better data to use in the design process.

Work measurement is an important part of business process engineering, or in some cases, re-engineering. The more knowns that a designer knows the more accurately and efficiently they can be in their final design. The goal is to make estimates that are as close to actual results as possible. Accurate work measurement can be considered one of the most important elements in their ability to do so. Work measurement is an integral part of the design process.

In conclusion, work measurement applies whether the worker is a machine or a human being. In many cases robots can perform work tasks more quickly and efficiently than their human counterparts. However, there are limitations to what machines can do. They cannot replace human reasoning, which makes it necessary to involve humans in many parts of the manufacturing process. The human factors in the environment add the greatest degree of variability to the system. However, with an adequate number of observations, even these factors can resemble knowns. Work measurement allows the engineer to turn a set of unknowns into knowns so that they can design a work system that is efficient and that meets the needs of the human counterparts in the best way possible.