ABSTRACT

In this work, the actual measured quality characteristics of Nigercem cement was considered. The ultimate objective of the study is to provide information that may be useful in hianagernent and control of production of high quality cement. The data was collected from the quality control department of the company. Statistical quality control technique used for this study is the process statistical quality control technique (by control chart device). A careful observation of the control charts of the four quality characteristics indicates that both process variability and process mean are relatively stable. For a more stable process variability and mean, the points that lie outside the warning and action limits was discarded and the control limit revised. At the end of the study, it was concluded that the company maintain a relatively stable quality standard for Nigercem cement. But for a more improved quality standard, the company should consider operating a quality control chart.

TABLE OF CONTENTS

Title i

Dedication ii

Acknowledgements iii

Certification iv

Abstract v

Table of contents vi - viii

List of tables and figures ix

CHAPTER ONE

1.0 Introduction 1

1.1 Background of study 1 - 4

1.2 Statement of problem 5

1.3 Rationale for study 5

1.4 Aims and objectives 6

1.5 Scope ofstudy 6

1.6 Literature review 6 - 7

1.7 Methodology 7 - 8

1.8 Organization of work 8

1.9 Definition of concepts

CHAPTER TWO

2.0 Justification of assumption 1 0

2.1 Test of normality on calcium oxide 10 - 11

2.2 Test of normality on silica 11

2.3 Test of normality gypsum 11 - 12

2.4 Test of normality on alumna 12 - 13

CHAPTER THREE

3.0 Investigation of process variability and process mean 14

3.1 Investigation of process quality 15

3.1.1 Constriction of process variability 15

3.1.2 Construction of process mean 15

3.2 Control chart for calcium oxide 15

3.2.1 Control chart for process variability 15 - 17

3.2.2 Control chart for process mean 17 - 18

3.3 Control chart for silica ' 18

3.3.1 Control chart for process variability 18 - 19

3.3.2 Control chart for process mean 19 - 20

3.4 Control chart for gypsum 21

3.4.1 Control chart for process variability 21 - 22

3.4.2 Control chart for process mean 22 - 23

3.5 Control chart for alumna 23

3.5.1 Control chart for process variability 23 - 25

3.5.2 Control chart for process mean 25 - 26

CHAPTER FOUR

4.0 Summary, Recommendation and Conclusion 27

4.1 Summary 27-28

4.2 Recommendation 28 - 30

4.3 Conclusion 30

Reference 31

Appendices 32 - 35