QUALITY IMPROVEMENT OF CHILDREN SHOES USING SIX SIGMA METHODOLOGY IN BABY WANG SHOES

• Main Author: Nadia Ciutara, Montella
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/39052
• Institution: Institut Teknologi Bandung

Baby Wang Shoes is one of small and medium enterprises located in Bogor which produces children shoes. The high numbers of order makes production activity happens in its every operational days regardless of its make-to-order basis. However, one major problem the company is facing now is numerous defects shoes produced in the company. In 10-day-duration, there are 1.510 defect units of 4.460 total production units which equals to 33,86%. Therefore, this research is aimed to design quality improvement solutions in order to reduce defect products in this company. The methodology used in this research is six sigma, consisting of define, measure, analyze, improve, and control. At the define stage, the research object is defined on children shoes for brand Baby Wang and Wang Shoes. According to the discussion with manufacture operators, there are five Critical-to-quality factors: machine, man, material, method, and environment. At measure stage, measurement of process stability and capability is done. Measurement of process stability shows that the process is stable with average defect fraction 0,3904, meanwhile measurement of capability process shows quality level of 1,76 sigma. At analyze stage, pareto chart is used to determine kinds of defect to be prioritized, resulting in sewing at fabric doesn’t suit specification, detached velcro, broken outsole, and stain. The defects causes are identified using fishbone diagram. Factors and subfactors contributing to product defects are traced with delphi method and failure mode and effect analysis (FMEA). The result shows some subfactors to be focused on in this research includes there is no guidelines about how to identify or solve causes of defects on the sewed shoes, lack of sewing machine cleaning, operators are not used to sew some shoes design, carelessness of operators in sewing the velcro part, operators don’t memorize shoes model details, and utilizing contaminated media for shoes moving. At improve stage, solutions are made and five solutions are accepted by the owner. This solutions includes establishment of standard operating procedure (SOP) to help troubleshooting causes of defects on sewed products, establishment of sewing machine cleaning routine schedule, balancing operators’ sewing line suiting to their own skills, shoes model photos in operators’ worksheet, and utilization of plastic pallet basket to move the shoes. At the control stage, supporting documents are created for ensuring the implementation of the solutions, such as SOP of sewing machine cleaning and SOP of plastic pallet basket utilization. The implementation of solutions requires managerial supports in some aspects like socialization and operators training, provision of investment fund, and periodic monitoring and evaluation of the solutions implementation results. A solution, establishment of standard operating procedure (SOP) to help troubleshooting causes of defects on sewed products is implemented and proven to have effective result in quality improvement which is shown by the increase of process capability to 2,10 sigma.