Statistical Quality Control of Manufactured Products

(Case Study of Packaging at Lifespan Pharmaceutical Limited)

C.N. Nnamani1, * and S.H. Fobasso1

1 Department of Mathematics, Ahmadu Bello University, Zaria- Nigeria

(SQC 16)

Abstract:

In the manufacturing environment, quality improves reliability, increases productivity and customer satisfaction. Quality in manufacturing requires the practice of quality control. This research work investigates the level of quality control in Lifespan pharmaceutical limited, makers of Lifespan Table Water.

The study involves inspection of some randomly selected finished products on daily bases. The data on the number of defective sachets were collected two times (morning and afternoon shifts) per day.

This was done for three weeks. The physical observations (number of defectives) from the company were analyzed using statistical tools such as Descriptive Statistics (proportion

and mean counts of defectives) and Control Chart for Attributes (P-chart and NP-chart).

The proportion of defective sachets per day was found to be 0.02634 with upper and lower control limits of 0.03708 and 0.01560 respectively.

Furthermore, this work shows that there are many points that fall out of the control limits. This means that the production process is out of control and needs a thorough and complete process inspection and verification. Even though the proportion of 0.02634 (which is about 3 defectives out of 100 every sachets) is not too high, the fact that the production process is not within control limits calls for a decisive action by the company.

Keywords: Water, Defective, Production, Chart.