Abstract:
To apply the steps of Six Sigma for improving two subjects. The objective of the first research is to improve the hardness of Jam. The case study of factory received complaints about the hardness of jam as 100% of the all product complaints. The research started with Measurement System Analysis (MSA). Descriptive Sensory Test and Just About Right Method (JAR) were used to determine the specification limits of jam hardness that were accepted by consumers. Next, the distribution of jam hardness was compared with the specification limits in order to determine the process capability as measured by process capability indices Cp and Cpk. The goal is to accept the values of Cp and Cpk of greater than or equal 1.33 and reduce the percentage of complaints to 0%. Brainstorming was performed to select the key input variables that affect the hardness of jam by applying the design of experiment (DOE) technique to analyze the effect of the significant factors and determine the values of the factors that yield jam hardness on target. Next, control plan and work instruction were developed to control the processes. After improvement, it was found that the Cp was increased from 1.39 to 1.6 and the Cpk was increased from 0.88 to 1.45. The number of complaints was reduced from 100% to 0%. The objective of the second research is to reduce wasted time of jam manufacturing process. The problem was that the factory could produce less than the customer demand approximately 9 batches per month or 14.75%. Thus, the manufacturing processes were improved to reduce wasted time by focusing on the delayed and transportation steps. Then, the production line was adjusted to be a continuous flow. After improvement, the cycle time was reduced from 9.12 hours per batch to 4.39 hours per batch. The average yield was increased to 61 batches per month that are sufficient to customer demand the number of man-hour from 6.76 hours per batch to 2.03 hours per batch. The capacity was increased to 180 batches per month.