Abstract:
The principle problem of process was found by VSM. The result showed that the MCT was too long, according to waiting times in assembly production line. Thus Q.C. story theory was operated to
improve processing. The process flow chart was used to identify the problem and this process found waiting time of materials occurred in adhesive dropping process. The work system and production
line was monitored and revealed that this system had acceptable precision and accuracy with standard level. Then, fish bone diagram was applied to analyzed principle causes and effects which resulted
in waiting time of materials. There were three suspected causes that were 1. shipping tray 2. buffer 3. machines layout. These causes had an effect on waiting time of materials in adhesive dropping
process, so the experiment must be improved by 2k Factorial Design. Thereafter, the result displayed that the optimized level of factor can reduce materials waiting time in adhesive dropping process.
In addition, this experiment showed the factor MCT being equal to 10.73% which decreased MCT from 9.88 hours to 8.82 hours, but there was error about 2.43%. According to changing shift,
preparation machines and investigation amount of materials in production line before starting production, so the experimental target cannot be achieved. Besides, the work in process had a decline to
22.89% daily. For specific standard, three factors were indicated as production standard. Moreover, the control established a control plan to set the quantity of raw materials to transfer between
production processes. The buffer size was also set to control the issue of raw materials and transfer raw materials to the production line. From this operation, the conversion cost was reduced to 214,862
USD per year.