Rao, Tumkur Raghavendra; Rao, Gururaja (1986, ASQC) Indian Telephone Industries Ltd., India
This paper deals with the Quality Circle Case studies of two important sub-assembplies of the telephone, namely Receiver and Ringer. The function of these sub-assemblies are "Convert signal" and "Attract attention" respectively. These sub-assemblies are required in a very large quantities and as such any quality problem encountered in its line causing rejections calling for rework or scrap, upsets the balance of the line. Therefore a Zero Defect concept is appropriate for these sub-assemblies. Quality Circles working in these areas took up this problem for study. A systematic application of quality control tools, like collection of up-to-date data, Pareto analysis to find out the vital few defects which mattered most, Cause and Effect diagram, Brain storming to find out the alternative ways of performing the same functions were used for analysis. In case of the receiver two types of quality problems existed, namely rejection due to functional defects, and rejection due to physical defects. In case of the former the analysis indicated that quality control at appropriate stages combined with the use of proper fixtures would yield the results. In case of the latter one of the major causes of rejection was improper stamping of code number and batch number. This was analyzed and a new process was suggested (use of sticker as an alternative to stamping) which eliminated the defects and improved productivity. In the case study of ringer, the analysis indicated that it is possible to control the deviation and bring down the rejection. However, the metallic rod of the hammer used in the ringer needed improvement. The brain storming technique was adopted to find out the alternative to this function. A plastic hammer with the metallic ball ultrasonically welded in position was suggested as an alternative. Field trials and endurance tests confirmed the effectiveness of the suggested method and completely eliminated the quality problems. Quality Circles of the respective areas came out with the solution keeping in view the practicability of the ideas, ease of implementation, increased productivity and reliability with improvement in quality. The suggestions have been implemented and the concept of Zero defect is achieved. Quality, the universal equation for excellence has been upheld.
Construction industry,Case study