Lb/DON I imj^^ University of Moratuwa Sri Lanka THE EFFICIENCY STUDY OF AN AUTOMATED SYSTEM - THE CASE OF A SRI LANKAN TYRE MANUFACTURING COMPANY 5 ' W T « ? ^ " V Master of Science in Operational Research S I oB__ Department of Mathematics University of Moratuwa 84249 AJ.Y.A. SAMANTHIKA August 2005 A2* THE EFFICIENCY STUDY OF AN AUTOMATED SYSTEM - THE CASE OF A SRI LANKAN TYRE MANUFACTURING COMAPANY AJ.Y.A. SAMANTHIKA This thesis was submitted to the department of Mathematics of the University of Moratuwa is a partial fulfillment of the requirements for the degree of Master of Science Department of Mathematics University of Moratuwa Sri Lanka August 2005 ii Declaration The w o r k presented in this thesis in part or w h o l e has not been submi t t ed for any other academic qualif ication at any institution. A T Y A Samanthika Prof. M. Indral ingum (Candidate) (Supervisor) • in Abstract This research is done to investigate the practical applications of Computer Simulation to analyze and solve frequently met problem areas in a tyre manufacturing factory. Automated solid tyre production line of Loadstar (Pvt.) Ltd. at Midigama factory was one such selected production line for this Research. The identified problem areas were, q u e u e f o r m a t i o n for u n l o a d i n g cured tyres i n o v e n l i n e s and resulted p r o d u c t i o n o u t p u t d e l a y s due to same reason and also due to other various reasons such as p o o r p r o d u c t i o n p l a n n i n g and d e l a y i n p r o d u c i n g r a w tyres etc. After an initial system study with the help of the production staff, I analyzed the above mentioned problem and discussed how to avoid those. Introduction of the 'Promdel' (Production Simulation Package) to build a computer simulation model for this problem area was experienced in this research as a smart proactive problem solving tool. And also, I introduced a better production - scheduling method for this process, using Heuristic method to replace the then used poor production planning method. With these changes, the result was; a provision of an easy proactive problem solving tool to try and find out the best allocation of ovens to get the least queue formation at the c o m p u t e r s creen to select the best possible array with an easy monitoring facility, before it is performed in real world at the production floor. So, S i m u l a t i o n w a s e x p e r i e n c e d as a smart r e p l a c e m e n t for a tedious; or rather irreversible, rigid, iv outdated, hit-or -miss procedure which left out at the end with no choice other than bearing up the very expensive loss of rejects and low outputs. A comparatively convenient way to allocate the available resources for an optimum increase of the productivity was the result of this exercise. 'Promodel' is one of the available simulation packages in the market today and for the study we used a student version of it. Expensive commercial versions may consist with more facilities for modeling to customize more closure to the practical needs of the organization. A wide survey of latest verities is advisable before an investment to buy a commercial version. Report consists with other suggestions to avoid the observed bottle necks at the press and the ways and means to improve and strengthen the supply chain of raw tyres also. Changes at the stage of factory wise or line wise allocation of the orders, line lay-out changes, and visual sign system to improve communication through out the supply chain of raw tyre production etc. are discussed in detail at the report. Acknowledgment I would like to express my sincere thanks to my Supervisor Prof. M. Indralingum, The Coordinator of the M.Sc in Operational Research of Department of Mathematics, University of Moratuwa. For sure, I may not have been able to complete the project successfully without the knowledge, advice, and guidance and kind support of him. And also, I would like to take this opportunity to thank, The Head of the Department and all the staff members of the Department of Mathematics, University of Moratuwa. I would also like to express my thanks to Mr.Tissa Jinasena , the Jt. Managing Director of the Loadstar(Pvt.)Ltd., Mr.Santha Herath, Senior Engineer, Mrs. Wimala Aravinthakumar, Industrial Engineer, Mr.Dishantha , Asst. Production Manager - Midigama factory, Mr.Sarath Kumara, Human Resource Manager and all other members who support me to success this project at Loadstar. ' ' ' • " ) ! • / .. u \ Specially, I would like to take this opportunity to express my thanks to Dr. Charnli Pushpakumara, Senior Lecture in Department of Industrial Management, University of Kelaniya. And also, I take this chance to express my warm thanks to Mr.Chathura De Silva , Engineering Trainee at the Laodstar (Pvt.)Ltd. Without their support, I may not able to compete this project successfully. It is my obligation to thank all my friends for their support and I gratefully acknowledge the support and encouragement given by my family. vi Comttteinife Title Declarat ion Abstract A c k n o w l e d g e m e n t Contents List of Tables List of Figures 1. Introduct ion 1.1. Problem Identification 1.2. Object ive 1.3. M e t h o d o l o g y 1.4. S u m m a r y 2. C o m p a n y Profile 2.1. Introduct ion of the C o m p a n y 2.2. Product ion facilities 3. Descr ipt ion of the Sys tem 3.1. H o w to s t u d y the real sys tem? 3.2. Descript ion of exist ing process 3.3. Exist ing A u t o m a t i o n System 3.4. Main i tems avai lable in the automat ion sys tem and their activit ies 3.5. Problems of the exist ing process 4. Operat ion Research (OR) Techniques w h i c h are us ing for this s tudy P a g e N o i - ii iii iv - v vi vii - viii ix x I 1 1 1 - 2 2 3 3 4 - 8 9 9 9 - 1 1 1 1 - 1 2 12 - 13 15 - 18 19 vii 4.1. Heuristic search technique 19 4.2. Simulation 19- 24 4.1.1. Definition of Simulation 19- 20 4.1.2. Advantages of Simulation 2 1 - 22 4.1.3. Limitations of Simulation 22- 23 4.1.4. Methodology of Simulation 23 4.1.5. Types of Simulation 24 Problem & Method of approaches 25 5.1. XL Sheet approach 25 5.1.1. Modified XL Sheet approach 2 5 - 26 5.1.2. Analysis of the above three XL sheets 26- 27 5.2. Simulation approach 27- 29 Simulation 30 6.1. Introduction of Promodel 30- 34 6.2. Explain the Building a model using Promodel simulation software 34 - 39 6.3. Analysis of problem using built simulation model 39 - 44 6.4. Analysis the Mould change & Breakdowns using Promodel simulation 44 7. Conclusion 45 7.1. Drawbacks of the existing system for allocating ovens 45 - 46 7.2. Drawbacks of the Oven line Layout 46 - 47 7.3. Drawbacks of the Supply chain 47 7.4. Drawbacks of the Existing Factory wide production allocation 48 References 49 Appendix I 50-53 Appendix II 54 - 77 vm List of Tables T a b l e s P a g e N o . A p p e n d i x I 1. Line p r o d u c t i o n capacity (a & b) 50 - 51 2. Line capaci ty for short cyc le p r o g r a m (a & b) 52 - 53 A p p e n d i x II 1. (a) Detai l Table of avai lable m o u l d s 54 1. (b) Modi f i ed detail table u s i n g P ivot table 55 2. Modi f i ed m o u l d al locat ion for their input t imes (a & b) 56 - 57 3. A c c o r d i n g to the input r a w tyres in 1st m e t h o d (a & b) 58 - 59 4. A c c o r d i n g to the input r a w tyres in 2 n d m e t h o d (a & b) 60 -61 5. M o u l d a l locat ion for cur ing t ime - 2.15 ( ( a ) part I & II , (b) part I & II) 62 - 65 6. M o u l d a l locat ion for cur ing t ime - 3. 00 ( ( a ) part I & II , (b) part I & II) 66 - 68 7. M o u l d a l locat ion for cur ing t ime - 3.15 ( ( a ) part I & II , (b) part I & II) 69 - 71 8. M o u l d a l locat ion for cur ing t ime - 3.45 ( ( a ) part I & II , (b) part I & II) 72 - 74 9. M o u l d a l locat ion for cur ing rime - 4.15 (a &b) 75 - 77 ix List of Figures Figures 3.1. Production Process of the Resilient Tyre 3.2. Process of Producing Band Tyre 3.3. Existing Automation System 3.4. Main activities of the available items 3.5. Moulding & Curing the process 3.6. Flow chart of the Production Planning P a g e N o . 9 10 11 14 15 18 4.1. Methodology for Simulation 23 6.1. Main Building steps in Promodel simulation software 31 6.2. Concept which have been used to develop the Simulation model 34 6.3. The runtime view of the simulated model 40 x