Determining the Statistical Process Control Limits for Uncertified Sri Lanka Standard (SLS) Boxes of Matches in Sri Lankan Market

Abstract

Quality control limits through Statistical quality control charts are used to control the quality of the process in product manufacturing. It can be used to determine whether the manufacturing process is operating according to the desired quality standards. Manufacturing boxes of matches should be in appropriate quality as it is considered the safety consuming item. This paper addresses the main objective of determining the statistical quality control limits for uncertified Sri Lanka Standards (SLS), boxes of matches manufactures in Sri Lanka”. Sub research objective is “to determine whether SLS Uncertified Boxes of matches are Really safety related to its production process.”. 1135 sample units of match sticks were used for the study using 25 samples for the study. Primary data were gathered using direct observation method from uncertified Sri Lanka Standards box of matches manufacturers regarding the considered quality characteristics in both variables and attributes in product. Eight quality dimensions such as the number of matches in a box, ignition and burning, afterglow, length of splint and match head, bending strength, were the considered quality characteristic of the boxes of matches. These quality characteristics were taken from SLS recommendations. Statistical Quality control equations, Statistical quality charts were used to analyse the data. Lower control and upper control levels of the characteristic of the SLS uncertified match boxes are as follows. Length of Splint 30.7 mm -34.8mm, length of the head 3.3mm -3.5mm, Burning time 13.8sec – 17.8 sec, Bending strength 35.1sec-40.7 sec, Afterglow 1.46 sec- 2sec, safety 0 -12.6, adherence

203 0-4.89, No of match sticks in the box 44-46 sticks. Generated quality control limits prevailed within SLS requirements except the quality dimensions, the Length of Splint and the Burning time. They highlight that these boxes of matches which do not have SLS are unsafe due to the uncontrolled production process based on SLS. Thus, the Sri Lankan manufacturers should draw their attention to produce full quality productions with a high priority to safety.