Case Study #4. CTD Analysis, Workplace/ Tool Design and Ethics. IE 327 Lab Report

Transcription

1 Case Study #4 CTD Analysis, Workplace/ Tool Design and Ethics IE 327 Lab Report Executive Summary: ClipCo, based in Wilkes Barre, PA, is a major manufacturer of flashlights and spotlights for both first responders and hunters. The company is concerned about the large number of cases of cumulative trauma disorders (CTDs) in the plant. These cases negatively affect both the productivity and finances of the company. In response, ClipCo is thinking of shipping the assembler jobs down to Mexico where the company pays the workers less and is not responsible for these injuries. To keep the jobs in Wilkes Barre, there would need to be a 20% increase in productivity. To resolve the issue of transferring to Mexico or staying in PA, a CTD risk index is calculated. This index includes four main factors that contribute to the result, which are Frequency Factor, Posture Factor, Force Factor and Miscellaneous Factor. This CTD risk index for the original job was calculated to be and with a 20% increase in productivity. These results verified the issue since the optimal CTD risk index should not exceed 1 for the job to be considered acceptable with a low risk of injury. The areas of concern that contributed to such a high CTD were the tools being used during the job, both the screwdriver and the wire cutter, as well as the work area, mainly focusing on the chair that the worker preformed the task in. Solutions to the concerns were to execute a redesign of the styles of the tools as well as a redesign of the work place. The new screwdriver reduced the amount of force needed and therefore reduced the rate of fatigue of the worker. The new wire cutter also reduced force and delayed fatigue which resulted in a decreased force factor. The redesigned chair helped to reduce strain on the back of the worker, as well as maintaining an elbow angle of 90 due to addition of arm rests. With these changes, the new calculated CTD risk index decreased to and with 20% increase of productivity. The whole process of the redesign will cost the company $28,800 for 200 assemblers, but spending $28,800 once to improve a work site is better than having to spend $50,000 or possibly more in medical costs due to injuries while still maintaining an unsafe working environment. Introduction:

2 ClipCo is a manufacturing company of flashlights and spotlights. There has been a large amount of cumulative trauma disorders or CTDs at their plant in Wilkes Barre, PA recently. 29 out of 200 assemblers have suffered from an injury that required at least one day off of work and ten of those assemblers have had required surgeries that need an average of eight weeks of recovery time. Annual Workers Compensation has reached $1,000,000 and each surgery averages at about $5,000 a case. The workers are paid anywhere from $6.50 to $9.00 an hour with an average of about $7.50. With the increase in injuries, Clip Co Company is considering moving the assembling jobs to a plant down in Cuidad Juarex, Mexico. Here the wages of the assemblers would fall to $0.60 an hour and the company is not responsible for injuries and Workers Compensation cost. A redesign of the job process, work environment, and tools can prevent the company from having to ship the assembler jobs to Mexico, while also decreasing the number of injuries to save the company money. With a redesign, the productivity of the company should still expect an increase of 20% while maintaining a low CTD risk index. Objectives: - Complete a CTD Risk Analysis by observing an assembler s job of making a flashlight - Focus on the wire cutter and screwdriver in the job and determine how to make these tools more ergonomic and efficient for the worker - Create a redesign for the assembler s job and determine if there will be an increase in production of 20% - Consider the costs and wages of workers at current plant and make decision if plant should be moved to Cuidad Juarex, Mexico Methods: First, we were presented a video of a worker and calculated the number of hand motions the assembler performed within a day, as well as analyzed the tools that were being used and the overall work station. From this analysis, we used checklists to evaluate the workplace, the wire cutter and the screwdriver. We also completed a CTD of the current job as well as a CTD for the current job with a 20% increase in production. Based on the evaluations, the CTD values, and our understanding of the job at hand, we created a redesign. The two values of CTD were again calculated for the redesigned job to conclude the results of a redesign. Finally, we analyzed the cost of the new redesign and decided if the job should be moved to Mexico or stay in Pennsylvania. Along with a cost-benefit analysis, ethical concerns were also taken into account when making this decision. Results: Table 1 show the CTD risk index values for both the original job site and the redesign in general and with a 20% increase in production. The index of the job changes from to from the original to the redesign and also changes from to from the original

3 to the redesign with the 20% increase in production. Table 2 shows the costs of the redesign. This includes the costs of the two new tools as well as the improved chair for both one assembler and the full 200 assemblers. Table 3 shows the cost of the surgeries for the injuries obtained at ClipCo. Table 1: CTD Risk Index for Original and Redesign CTD (original) CTD (redesign) Frequency Factor Frequency Factor (20% decrease in cycle time) Posture Factor Force Factor 2 1 Miscellaneous Factor CTD Risk Index CTD Risk Index (20% increase productivity) Table 2: Costs of Redesign Cost of Cost of Wire Cost of chair ($) Total cost ($) Screwdriver($) Cutter ($) One assembler assemblers 1,000 1,800 26,000 28,800 Table 3: Surgery Costs Surgery cost ($) One assembler 5, assemblers 50, assemblers 1,000,000 The redesign of the screwdriver was based off an analysis of a select few screwdrivers to be considered. The subset of screwdrivers that were decided upon, were D, F, H, and I. These four screwdrivers were chosen based on their ergonomic value, including the handle and grip, as well as the accuracy and precision ability of the tool. All of the screwdrivers that were selected had either wooden, plastic or rubber handles, where all three materials decrease conductivity and increase friction. The worker also needed a screwdriver that would require the least amount of force to complete the task. We analyzed all four screwdrivers to determine which one would be easiest for the worker to use. Screwdriver D had a no slip grip, having rubber on the handle, to make handling the tool easier and had a moderately thick handle which creates a large contact area. However, the

4 handle was short in compared to the length of the entire screwdriver, making it less stable and precise during use. F also had a no slip grip with a rubber handle and had a longer handle than D, but the thickest part of the handle is at the bottom instead of where the middle finger makes contact with the handle which increases the force needed to use the screwdriver. H is a shorter screwdriver which is beneficial for precision, but H is not every ergonomic with a plastic grip and no form fitting handle. Screwdriver I would create the most accuracy by having a longer handle compared to the entire length of the screwdriver which leads to the most control from the handler. I is not the most ergonomically efficient screwdriver since it has a wooden handle and does not contain the best grip. Ultimately, screwdriver I, shown in figure 1, was chosen as the best tool for this job. In the hand, the middle finger is the longest and strongest finger. Screwdriver I is designed to use the middle finger to its maximum due to the shape of the handle. The handle leads to the largest contact area with the middle finger which would result in good precision and the least amount of force needed by the worker. Also, for a screwdriver, the optimal grip should be 1.5 inches in diameter allowing the fingers to barely overlap during a power grip. Screwdriver I has around a 1.5 inch diameter which would make it a very efficient tool. The focus of the redesign for the wire cutter was ergonomics. The optimal dimensions for this type of tool include a grip span ranging from 2 ¾ inches to 3 ¼ inches, averaging around 3 inches, and a handle that is at least 4 inches in length. The wire cutter should also have bent handles to allow for a straighter wrist during use. The wire cutter we have chosen is shown in figure 2. These wire cutters were chosen because of their ergonomic value and cost efficiency. The length of the wire cutter is 7 inches, making the handle approximately 5.5 inches which is considered optimal for this product. The grip span of the redesigned wire cutter also falls in the optimal range at 2.75inches. According to the Xuron Corp website, the grip design of this product keeps the knuckles of the workers hand in a straighter line and prevents the hand from completely closing. This reduces the amount of effort needed while delaying fatigue. This product is also available for left-handed workers as well. This is extremely beneficial to the company because if a left-handed employee needed to use a right-handed tool, the strength they can exert is decreased by 10% which would result in less efficient work and faster fatigue. The workstation needed to be redesigned as well to further improve the job. According to the workstation evaluation sheet, the biggest issue with the workstation was the chair. The chair was positioned at an uncomfortable height and had no arm rests, foot rests, nor a practical back support. A standard comfortable chair is adjustable, contains a back rest to keep your spine in an S-shape rather than a C-shape, and contains arm rests to get a 90 angle of the elbow onto the table which is the optimal position. The new redesigned chair is shown in figure 3. This chair provides significantly more back support to the worker, contains armrests to maintain the optimal elbow angle of 90, and is adjustable for different workers.

5 Discussion: The data for a cost analysis on the redesign is shown in table 2. The redesigned screwdriver would cost an estimated $5 each, the new wire cutter comes to $9 each and the chair is approximately $130 each. This comes to a total cost of $28,800 for the company to supply the redesign to all 200 assemblers. Although ClipCo mentioned that it did not want to spend a lot of money, the company should realize that in the long run, this redesign will be incredibly financially beneficial towards them. With the current design, 10 out of 200 assemblers needed carpel release surgery which resulted in an 8 week long recovery. Not only is the company loosing $50,000 for the cost of surgery, referring to table 3, for these employees, but it is also losing about 3,200 hours of production. Spending the $28,800 on a redesign will save ClipCo a loss of $50,000 and will maintain, if not improve, production. The new design of this job improved the CTD risk index to an acceptable value. Table 1 show that the original CTD risk index was which is an unacceptable value since it is greater than 1. With the application of the redesigns, the new CTD risk index has a value of which is less than 1, making it an acceptable value. Applying the 20% increase in productivity to the original tasks results in an even worse CTD risk index of For the redesign, the CTD risk index value for a 20% increase in productivity was which is slightly greater than 1, deeming it unacceptable. However this CTD risk index value is still lower than the original job without a 20% increase in productivity which depicts the efficiency of applying this redesign. The redesign of this work place resolved the issue of the CTD risk index being too high. With that issue out of the way, ClipCo should keep the Wilkes Barre Plant open instead of shipping the assembler jobs to Mexico. If the original job was moved to Mexico rather than being redesigned, the CTD risk index would still remain too high, resulting in just as many injuries, if not more, of assemblers in the contracting plant in Mexico. This, in turn, would cause a decrease in productivity and would therefore be hurting ClipCo rather than helping them. Despite the productivity and risk indexes, ethics also comes into play immensely in this situation. The workers at the Maquiladora plant in Ciudad Juarez, Mexico are predominately woman and are only paid $0.60/hr, compared to the approximately $7.50/hr paid to workers in the PA plant, to assemble these flashlights in a workplace that is already calculated to be unsafe for workers. Not only would ClipCo be endangering Mexican workers, they would also be causing 200 people to lose their jobs. In considering, long-run benefits versus short-term costs, productivity, and ethics, it is clear that it is sufficient for ClipCo to keep the Wilkes Barre Plant open In Pennsylvania.

6 Figure 1. Redesigned Screwdriver Figure 2. Redesigned Wire Cutter

7 Figure 3. Redesigned Chair Recommendations: The original job produced a CTD risk index of 1.338, which is significantly higher than the acceptable value of 1 and, even with this CTD risk index, ClipCo needed to increase productivity by 20% in order for the plant to maintain in Wilkes Barre, PA. Since the risk index was already too high before the increase in production, a redesign of the workplace needed to be constructed for the plant to consider staying in PA rather than relocating to a Malquiladora plant in Mexico. Two of the main tools used, the screwdriver and the wire cutter, were redesigned, along with some changes to the work place to create an acceptable CTD. A CTD of resulted using the redesigned job with an increase in production by 20%, and a CTD of with the redesign without an increase in production. These values are acceptable CTD risk index values in a work place. The cost of implementing this redesign is $28,800, compared to a possible loss in $50,000 worth of injury costs with the original design, or a loss in productivity by moving the plant to Mexico. It is prevalent that the cost of the injuries overpowers the cost of the redesign and using the new design would create a safer environment and will save ClipCo money. The ethical aspects of affecting the Mexican workforce and putting United States citizens in unemployment also adds to the benefits of redesigning a job that is actually safe for everyone and will be financially beneficial in the long run. Due to the cost-benefit analysis and economic and ethical implications, the final recommendation to the IE manager of ClipCo would be to carry out the redesign of the job and maintain in PA. Bibliography: Figure 2. Figure 3. Black/product-nr_570621

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11 CTD RISK INDEX ORIGINAL 20% decrease in cycle time CTD Risk Index=.3( ) +.1(.33) = 1.449

12 CTD RISK INDEX REDESIGN 20% decrease in cycle time CTD Risk Index=.3( ) +.1(.33) = 1.089