Critical Thinking

Learning from Mistakes and How to Prevent Them

Gerald J. Watson Jr., Jesse J. Derouin

• Publisher: CRC Press
• Year: 2020
• ISBN:
  9781000076585
• Edition: 1
• Topic: Philosophy
• Subtopic: Critical Theory

Mistakes occur for many reasons. This book takes a hands-on approach to the reasons mistakes happen, analyzes the actual mistakes, and develops a strategy to reduce them.

This book proposes error reduction strategies in human decision making and educates the reader to further reduce the likelihood of making a mistake. It provides error reduction strategies, describes various cost-effective methods for eliminating costly errors, and discusses Anthropometry, Crew Resource Management, Human Factors, Industrial Engineering, Scientific Management, and Usability and the role these topics play in the avoidance of mistakes.

This book will be of interest to professionals and students in the areas of industrial engineering, human factors, logistics, quality control, manufacturing, human resources, and safety.

1 In a Hurry to Get the Task Completed

During the summer after barely surviving junior year at college, I was working at my father’s gas station primarily pumping gas and changing oil. I had recently taken courses in productivity, bottleneck theory, and value stream mapping, and was thinking of how I could apply that knowledge to the current tasks. My father was in the next stall replacing a drain plug manually with a torque wrench, ensuring that the plug was tightened to the correct torque as per specifications. Aha! I thought, what a waste of time! I could use a pneumatic wrench to reduce the replacement time significantly and productivity would soar. My father looked at what I was about to do and suggested against it. I was not deterred—after all, my father was not a rising senior at an engineering college. Well, a few seconds later, I realized that I had stripped the drain plug and the use of the pneumatic wrench was probably not such a good idea. I looked sheepishly at my father who said that he would need to go and buy an oversized drain plug that I would have to pay for. Finding an oversized drain plug in pre-Internet days required many phone calls and involved a lot of travel time.

After finding and installing the plug, the next requirement was to guarantee that the oversized plug did not leak. I then explained to the car’s owner what I had done and the motivation behind it. In an attempt to compensate the owner, I paid for the oil and filter change and filled the fuel tank with gas. As the car was being driven away, I realized that the time and money I thought I was saving was more than offset by looking for and obtaining the oversized drain plug. This does not even include the cost of the plug and the gas. What is worse and cannot be measured was the humiliation of committing such a mistake. After all, I had survived many hours of math, chemistry, and physics. What was missing?

Despite all the courses and associated laws in chemistry, math, and physics given at my college, my father asked whether students study Murphy’s Law. I responded with questions concerning the possible originator of that law: Newton, Edison, Tesla, Galileo, or Einstein? My father responded that before implementing a decision, the decision maker must think of what can go wrong, because if it can, it will, and at the worst possible and least expected moment. This is known as Murphy’s Law. According to an anonymous 50–50 rule, the 50–50–90 rule: anytime you have a 50–50 chance of getting something right, there’s a 90 percent probability you’ll get it wrong.

If I had thought through the process ahead of time and realized that a stripped drain plug could result in expensive, timely, and humiliating consequences that would cause more than the few seconds that it would save, then I would never have used the pneumatic wrench. Thus, I committed the mistake because I was in a hurry to get the task accomplished as I wanted to impress my father with all the knowledge I had gained concerning productivity to help justify his college expenses. I did not think critically about the negative consequences of the action that could occur and only thought about the positive results. This is the step that results in a majority of the mistakes that I had personally committed and witnessed.

During my professional career years later, I had the privilege of working as an outside employee at a plant, which hired an industrial engineering consulting company to install an incentive system for its 400 plus employees. An individual incentive system was established for each department over a period of several weeks. Anyone who did not meet the production standard within a specified period of time was subject to termination. My role as an outside contractor was to confirm the fairness of the incentive rates.

As an industrial engineer with many years of experience in the establishment of incentive rates in both union and non-union plants, I realized after several weeks of studying and analyzing the rates, that they were fair, and reported that to the management.

At a minimum, based on my experience, the mistakes made in this implementation were as follows:

1. Plant production personnel were not informed prior to the consulting group entering the plant to establish incentive rates. The incentive rates were to be established by members of the consulting group performing time and motion studies using the existing methodology.
2. No production personnel were given an explanation of the time study, its purpose, its use, and why it was being conducted. No operator was asked permission to be studied. No completed study was discussed with the operator or his supervisor for their input.
3. Neither the plant industrial engineer nor any supervisor were involved in the methodology or the establishment of the rates to enable them to answer the questions from employees during the establishment of or after the rates were established.
4. Training did not occur for those employees on or below the threshold of being terminated or those desiring to increase productivity.

These mistakes prompted the employees to discuss the feasibility of unionization and invite union representatives to hold meetings to do so. It also resulted in costly management meetings with all supervisors, with the need for an out-of-town labor attorney to have a proper conversation with employees, and consequently delayed shipments and cost overruns. These management meetings were mandatory and resulted in a lack of supervision on the production floor.

These mistakes were preventable and were the result of several factors, with the main one being the desire of the management to implement the incentive system as soon as possible in order to reap the economic benefits. The management failed to think critically through the situation to determine the worst possible outcomes. In the end, this failure cost the employees, the vendors, the community, and the company.

As an industrial engineer, I have installed several incentive systems, and, in my opinion, an incentive system is beneficial only if it is fair to the employees first and to the company second. However, before the company can begin installing a system, the employees must first become educated as to when and why this is implemented and then become consistently updated during the entire process.

I was once involved in implementing an incentive system in a sewing department of a furniture plant that had 26 employees, which required six months to implement: four to acquire the data and two to validate the data. The industrial engineering staff consisted of two full-time industrial engineers and a part-time technician. The engineers would check and ensure that each operator was trained on identical products on different days at different times to guarantee consistency of results. Time studies consisted of no fewer than 20 observations, with means and standard deviations computed to confirm all times were within two standard deviations (95 percent of the data). If not, then the study was not used in the final calculations. Studies were also conducted on two types of material to ensure that there was no statistical difference in sewing times between the two. In addition, sufficient studies were undertaken during the sewing of straight seams versus curved ones to ensure that there was no statistical difference between the two. Both studies were confirmed with a test of hypothesis at the 0.05 level of confidence using the t-test. Only studies that met those criteria were included. In addition, a trainer was hired to make sure that everyone could meet the new production standards. In the first two weeks of the new incentive system, many employees received the higher of the two wages. The trainer then worked with those employees who had not earned a higher rate and those who desired to increase their earnings.

The incentive system I installed required six months to replace the existing one in this furniture plant. The time granted for implementation was probably excessive, but the system that was being replaced was poorly designed and maintained. The plant manufactured low-end dinette furniture in various sizes and styles that were upholstered in fabric or vinyl. The company manufactured swivel chairs as well as chairs and barstools with four legs. The size of seats varied, but for some unknown reason when incentives were provided, three sizes were established: small, medium, and large. Initially, there must have been documentation as to which styles had a small seat, those with a medium, those with a large, or the dimensions that differentiated each, but over time these dimensions or the documentation were lost. So one day, a seat could be small and the next day the same seat could be medium or large depending on the mood of the supervisor. The different sizes had different pay rates under the old incentive system.

One mistake I observed was on a line that assembled vertical blinds for sliding glass doors or windows. The assembly operation consisted of six different independent operations, each consisting of one operator. When the operator completed the assigned task, a pre-glued barcoded label was attached, enabling him to earn an appropriate number of standard hours for that operation. Should that operator not have available work at any time during his shift, he noted the time started and stopped and the total time he was unable to work due to a lack of product availability. The downtime sheet of paper was submitted with his earned hours sheet daily to his supervisor. The employee’s pay for that day was calculated by multiplying the earned hours, adding his downtime hours, multiplying by his hourly rate, and then summing the two.

The mistake was due to the disproportionate amount of time as a percentage of the total time the operators spent in completing the downtime report. I conducted a sampling of the work and concluded that each operator spent 40 percent of the time manually computing information on a downtime report, which equates to over three out of eight hours in a non-value-added effort. Three out of eight hours equates to over a fourth of the entire operator’s workday that was not consumed productively. In terms of operators, the line had two operators who were not needed. I suggested a group incentive system, eliminating all the production staff from the beginning to shipping and relocating the line adjacent to shipping to reduce storage space. Due to the methodology of determining the labor standard, it was not possible for the initial operation to have downtime since unavoidable delay was one of the personal factors built into the standard. This was a costly mistake and occurred because of the failure to consider all aspects of the project.

An important concept in industrial engineering is value stream mapping. In a motion study of bricklayers, Fred Gilbreth stated that one of the steps in eliminating the rule of thumb and adopting and developing scientific knowledge is to eliminate all unneeded, false, slow, or useless movements [7].

Gilbreth simply explained this concept to his students: handle a product no more than it is necessary. The optimum number of times is one as the product is assembled and packaged for shipment. To prevent unforced idle time and/or bottlenecks, the assembly line must have sufficient availability of products to each employee on the assembly line to enable a continuous work flow. Each employee on the line must be trained on each task on the line to enable him to assist as needed for a continuous flow of product. I worked for a furniture company in which the engineers joked that the company wore out the furniture before it was shipped to the customer due to the excessive number of times it was handled in the plant.

One aspect of the job I enjoyed was working as a part-time salesman. This provided an opportunity to meet new people and observe different operations. Often, I was able to assist a customer in reducing their material handling costs by working with local engineers or by purchasing to reduce lead time or order quantity. I called on a huge company that produced automobile tires in an adjacent state, which was currently supplied by a competitor. The company consumed more than two truckloads of tubes per week delivered on racks with casters. Obtaining this customer would add an additional plant for the manufacturer my company serviced.

I met the purchasing agent (PA) and after reading the specifications, I quoted him a price per thousand (M), free on board (FOB) customer, and shook his hand in agreement while looking him in the eye. The meeting occurred on a Monday, and he placed an order due the following Monday. Since there were several other calls that I needed to make to other customers, I did not return to the office until that Thursday to follow up with a formal written quote.

As I was calculating the price, I realized that an error had been made in favor of the customer. I quoted a price of X, but according to the formal quote, it should have been X plus 10 percent. I cursed myself for making such a careless mistake. Then, I thought about what should be done.

Luckily, my boss, the president, was in the office. So I went to see him to discuss the situation. After all, he was the president and was paid the big bucks. When I told him about the error and the extent of it, he just looked at me and told me that this was funny. He then stated that he hired me because he thought I was smart since I had gone to an engineering college but realized that he had made a stupid mistake in hiring me. He even reminded me that I had earned a master’s degree from the engineering college. He then told me to leave his office so he could call his college buddies to tell them that his “smart” engineering college graduate made stupid mistakes like everyone else.

Needless to say, I was shocked at his reaction since at the very least I expected an unpleasant discussion, if not termination. I again reminded the president that at that price the company would lose money but mentioned that a formal written quote had not been sent to the customer. He said that did not matter and asked if I had looked the customer in the eye and shook his hand. When I replied that I had, the president responded that honesty, integrity, and respect once lost can never be regained, but money can always be recouped. When I again reminded him that the company would lose money, he responded that a deduction would be taken from my salary to cover the loss. When I told him that the salary would not cover the loss, he joked that he would simply give me a raise. When I asked how the company would compensate for discrepancies in prices in the long term, his simple reply was that when the company gets a general increase in rate of X, the company will increase their prices X plus 1 percent and eventually the difference would be eliminated. But again he emphasized that the most important thing was not money, which could easily be replaced, but honesty, integrity, and respect, which once lost were difficult, if not impossible, to regain.

No one in the company ever mentioned this simple math error. However, when I was at the corporate headquarters, I was fair game when performing calculations. Any of the executives enjoyed approaching me with a slide rule asking if I needed assistance with addition or subtraction, knowing that those two functions cannot be performed on the device.

This error was definitely avoidable. I did not take the few extra minutes to double-check the calculations nor use critical thinking to determine the results of an inaccurate quote, which I had done in such a hurry to provide it to a new customer.

Since foreign automakers were successful in selling automobiles with diesel engines in the United States, a local automaker during the latter part of the 1970s decided to create a new range of diesel engines that would not be subject to the new federal stringent emission and mileage standards that came into force in 1972 and became more and more stringent over time. The company assigned one division to achieve this while delivering the fuel economy and performance demanded by customers. Since diesel engines obtain their power using a compression ignition system, gas laws from chemistry dictate that the temperature of a gas and its volume are inversely related, provided that the volume of the gas in the combustion chamber decreases, then the temperature increases. Thus, diesel engines require higher compression than a gasoline engine. Since the bolt pattern was not changed, the head bolts stretched and the coolant could leak into the cylinders causing catastrophic, internal damage to the engine.

This mistake occurred because the company rushed to get the conversion from the gasoline engine to the diesel engine. If critical thinking had been performed, it would have resulted in proper research that would have recommended a different head bolt pattern to withstand the higher pressure needed for compression in diesel engines. Critical thinking would also have pointed out that a common problem with diesel fuel at that time was that it was often contaminated with water. The solution would have been to install a water separator, but this was omitted to save money. The absence of the water separator resulted in corrosion in the injection pumps, fuel lines, and the injectors themselves [11].

There were other issues as well. Although this diesel was produced for a limited period of time, from 1978–1985, the losses that resulted are difficult to measure. The company lost its prestige, and numerous class action lawsuits were filed: some lawsuits reimbursed owners for as much as 80 percent of the costs of a new engine, some lawsuits established Lemon Laws in all states, and the reputations of diesel engines were tarnished for buyers at least temporarily.

These mistakes resulted from the failure to understand the importance and significance of human factors in the workplace. I encourage readers to investigate this topic further, first by reading the information under Human Factors at the Appendix section of this book and through further research and coursework.

2 To Meet a Deadline

The first set of questions to ask are: Whose deadline is it? How did it originate? Is it realistic? A management tool referred to as the Program Evaluation and Review Technique (PERT) can be and is often used to schedule, organize, and ensure that tasks are accomplished. This technique actually originated in 1958 with the development of the Polaris missile. The use of this method requires the listing of each activity that must be performed in the completion of a project, and equally important the time required to perform the activity from the beginning to the end of each task. The benefits of using PERT include the facilitation of decision-making as well as a reduction in the time and costs to make a decision. Each task in the project will be dependent on some tasks which can be performed in parallel with others and some sequentially.

To determine the time taken for each task, PERT uses three definitions: optimistic time, which is the least amount of time needed to accomplish a task or an activity; most likely time, which is the best estimate of how long it will take to accomplish a task or an activity, assuming there are no problems, or the time that has the greatest probability of occurring; and pessimistic time, which is the best estimate of the longest time that it will take to accomplish a...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Preface
• Author
• Introduction
• Chapter 1 In a Hurry to Get the Task Completed
• Chapter 2 To Meet a Deadline
• Chapter 3 Failure to Consider All Costs of the Operation
• Chapter 4 Failure to Consider All Aspects of the Project
• Chapter 5 Failure to Ask Others for Assistance
• Chapter 6 Conclusions and Recommendations
• Appendix: Topics for Additional Information
• References
• Index