Quality is about an excellent product or service that fulfills our expectation or requirement. These expectations are depend on the intended use and the selling price. When a product meets our expectation, we can consider the product has the quality. Quality can be improves by several method such as failure mode and effect analysis (FMEA), quality function deployment (QFD), and benchmarking. In order to improve the quality of a product or service, the problems that affect that quality need to be determined. In determine those problems; we may use the statistical process control (SPC) tool such as Pareto diagram and the cause-and-effect diagram. In this context, we had been evaluating the quality issues in Honda Production Line by using these tools. The evaluation process is done by using the data of defected parts for month April, May, June and July 2015. The Pareto chart constructed in order to determine the critical problem face and it is constructed using the stated data. The critical problem regarding the quality issues in Honda Production Line are determined as dented and humped of the parts. This two problems quite similar and thus only one combined cause-and-effect diagram constructed. Construction of this diagram is a way in define the root cause of those problems.
Since 15 November 2000, a partnership between Honda Motor Co. Ltd. of Japan, DRB-HICOM Berhad and Oriental Holdings Berhad resulted in the birth of Honda Malaysia Sdn Bhd, a company committed to offering the “Highest Customer Satisfaction in Malaysia”. Since then, Honda Malaysia has been a solid and aggressive player in the Malaysian automotive market. Each year, it progresses so IOrapidly that it set up a plant in Pegoh, Melaka. With this new plant, not only is Honda Malaysia optimistic of achieving high sales every year, it has further strengthened Honda’s reputation in Malaysia.
Honda Malaysia Sdn Bhd is one of the biggest companies in car manufacturing. Every day, Honda Malaysia Sdn Bhd produces approximately around 200 units of cars. In industry involving high target of mass production, established company such as Honda too are not able to avoid quality issue in production line. There are many factors affecting the issue of the quality and one of the major factors is the defect of components. Whenever defects were detected during production, operators’ job process needs to be interrupted in order to deal with the defects item either to repair or to sort it out to other section. Due to the situation, technically, every time defects were encountered, man-power that initially should be focused on the production will decrease and causing a delay to the production line.
Data were collected from my friend who made his industrial training with Honda Malaysia Sdn Bhd. From him, we acquire information such as losses, number and type of defects for each rejected components. Figure below shows example of form of data we obtained.
From data obtained, we extract information we need in order to carry out analysis and in our case, we just need the total number based on type of defects for the whole month create a table with those information in it. After extracting data, we analyze the information by using two kind of method, first is by using Pareto chart and secondly, by using Cause and Effect diagram or also known as Fish Bone Chart or Ishikawa diagram.
Data was collected during the industrial training at Honda Malaysia. These data are mainly about the problems that faced by Honda when they received components or parts from their suppliers. Honda used sampling inspection method to determine defective items. They took a sample of items for each lot to be inspected. The result of the inspection was monitored using check sheet that controlled by the quality department. The result also was tabulated and graphically plotted to analyze the performance of the suppliers. In Honda, the inspection process was divided into three major area which are inspection of incoming parts, inspection on assembly line and inspection on finish product. But, as mentioned earlier, quality department was focusing on inspection of incoming parts.
In this analysis, we have focused on the number of defective items for each defect that commonly happened. We selected the related information from data available and reconstructed the table of the summarized data. Below are shown the original data information that provided by quality department of Honda and our summarized data that we chose to be analyzed in this short project.
We used SPC tools which are Pareto Chart and Cause-and-Effect diagram as our analysis techniques. There are a few steps that need to go through in order to create a Pareto Chart. The Steps are as follows:
- Define the problem by using brainstorm or data available.
- Select a time period.
- Identify problems clearly which we study on it.
- Create graphic bar of each problem in horizontal axis and cumulative percent on the vertical axis.
- Horizontal axis is divided into a number of equal bars. Each bar presents the different problem.
- The cumulative percent of each bar place on vertical axis is based on the frequency of each problem.
After all these steps above, we can defined the most important reason of problems which is until 80 percent.
For Ishikawa diagram, there are two general steps which the first step is defining the problem by giving brief information and the second step is creating factors or causes that that related to the problem. This part can be created by asking some questions such as ‘Which factors lead this problem?’ or ‘What is relationship between these problems?’ or by using round robin method. In round robin method, 6-3-5 technique will be used. According to this technique, 6 people should create 3 idea in 5 minutes. Below are stated a few steps to create a cause and effect diagram:
- The arrow should be drawn on the paper.
- Problems should be written on the head of arrow.
- After that small arrows should be drawn on the main arrow.
- Main reasons should be written on the small arrow.
- Main reasons should be detailed under their arrow.
- In the end of each cause is connected to each other if they are related and find cause of problem.
As shown the results on the data analysis part, Honda Malaysia Sdn Bhd (HMSB) has quality issue on their some outsources materials. Their temporary solution is repairing those materials which have defect. If we summarized the repairing works, the total quality repair cost is around RM 7967 for three months. Besides the cost, it is about company prestige.
In this work, we used Pareto diagram to identify the critical problem and cause and effect diagram to identify the root cause of the critical problem. Before that, problems were categorized based on the type of defects.
According to Pareto principle, for many event, roughly 80% of the effects come from 20% of the causes. For this reason we focus on the problems which reason of the 80% of problems. We can see the defects on graphic as follow:
When we apply Pareto principle on that graphic, it is seen clearly, hump defect and dent defects constitute large part of the problem. If these two problems are solved then we can say that HMSB will be solved its most of problems. In this context we created cause and effect diagram as below:
Cause and Effect diagram or on the other word Ishikawa diagram is kind of quality diagram. It is one of seven quality tools. Purpose of using cause and effect diagram is work on the reasons of consequences, shows that reasons and makes them visual. In cause and effect diagram, reasons should divide as main categories.
In our case these main categories are identified on four titles as Workers/Operators, Machines, Transportation and Secondary Racking.
For worker and operator, after observation and brain storm in group members, we realized that operators who work on unload process of materials, have lack of training in part handling which is trigger second sub-reason. Most of the people who work on unload process, select randomly and they are not qualified workers for this process .Second sub-reason under operators’ part is that, theyare careless in work. They behaves are not elaborate for unload process. Some materials get dent because they don’t pay attention while they put materials on the lift or storage. Focus problem can depends on worker situation while during day which third sub-reason.
Next, for machine, we identified two sub-reasons under machines’ title. One of them is “spot weld problem” and other one is “stamping problem”. The company must have maintenance schedule like orderly. They can reduce problems which based on machines. Saving machines mean saving works.
For transportation, we have three sub-reason under the title of transportation and two of them happen, because of the supplier. In that case HMSB doesn’t have many choice about supplier. The other reason of transportation problem is “improper unloading process”. However this time, unloading process has problem not because of workers, it is because of transportation vehicle such as forklift, conveyor etc. If vehicles are not reliable then they should not be used for transportation.
Other than that, for secondary racking, materials wait for temporary until the time that they will be used. Conditions of the waiting area are the most important factor of secondary racking. Inappropriate racking design leads material to get hump or dent from environment. There is chance to drop something on them if they hold open area. And if used unsuitable wrapping technique for covering materials, it would be easy to get some defects from area. There are different techniques for covering different materials.