ADVANCES in NATURAL and APPLIED SCIENCES

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1 ADVANCES in NATURAL and APPLIED SCIENCES ISSN: Published BYAENSI Publication EISSN: April 11(4): pages Open Access Journal Improving Industrial Performance Using Lean Tools And Operations Research 1 Hariram VR, 2 Karthick B, 3 Rahul Prasad R, 4 Syed Thameem U, 5 Thajes P, 6 Veneeth A 1,2,3,4,5,6 Department of Mechanical Engineering, SNS College of Technology, Coimbatore. Received 28 February 2017; Accepted 22 March 2017; Available online 25 April 2017 Address For Correspondence: Hariram VR, Department of Mechanical Engineering, SNS College of Technology, Coimbatore. hariram.mech@gmail.com Copyright 2017 by authors and American-Eurasian Network for Scientific Information (AENSI Publication). This work is licensed under the Creative Commons Attribution International License (CC BY). ABSTRACT It is evident that the small and medium scale industries have inefficiency of operations. Such industries also witness further problems such as changes in demand, low productivity and more wastage. To eliminate such wastes, lean manufacturing technique is implemented. In this study lean tools Value Stream Mapping and Kaizen were used to identify and remove the wastes. Decision Making is the key factor in Lean Manufacturing. Thereafter sequencing of jobs (an Operations Research technique) was used to reduce time taken for production thereby reducing the cost. Hence, the overall performance of the industry was improved by employing lean tools and sequencing technique. KEYWORDS: Kaizen, Value Stream Mapping, Non Value added Activities, Lean. INTRODUCTION Lean is a production practice that considers the cost of resources for any goal other than the creation of value for the end customer to be wasteful, and thus a target for elimination. Working from point of the customer who consumes a product or service, value is defined as any action or process that a customer would be willing to pay for. [3]. Lean manufacturing is a variation on the theme of efficiency based on optimizing flow; it is a present-day instance of the theme in human history towards increasing efficiency, decreasing waste, and using empirical methods to decide what matters, rather than uncritically accepting pre-existing ideas. In order to depict and improve the flow of inventory and information, the lean tool Value Stream Mapping (VSM) was used. The VSM is a planning tool to optimize results of eliminating waste. To attain the objective of minimizing the time taken for completing the product, the operations research method of sequencing is employed. [1] [4] did Value Stream Mapping in a Rope Manufacturing Industry where the Lean changes were applied to the information flow system, as well as the material flow system, to reduce the total time required from the time an order is received to the time the rope is shipped to the customer. [3] analyzed the performance from supplier aspects in Volvo, Toyota and Volkswagon, where the supplier integration is seen as inevitable role in improving the performance. Value Stream Mapping: A value stream is defined as all the value-added and non-value-added actions required bringing a specific product, service, or combination of products and services, to a customer, including those in the overall supply chain as well as those in internal operations. [6]. VSM is an enterprise improvement technique to visualize an entire production process, representing information and material flow, to improve the production process by identifying waste and its sources [5]. ToCite ThisArticle: Hariram VR, Karthick B, Rahul Prasad R, Syed Thameem U, Thajes P, Veneeth A., Improving Industrial Performance Using Lean Tools And Operations Research. Advances in Natural and Applied Sciences. 11(4); Pages:

2 296 Hariram VR, et al., 2017/Advances in Natural and Applied Sciences. 11(4) April 2017, Pages: A value stream map (AKA end-to-end system map) takes into account not only the activity of the product, but the management and information systems that support the basic process. This is especially helpful when working to reduce cycle time, because you gain insight into the decision making flow in addition to the process flow. The basic idea is to first map your process, then above it map the information flow that enables the process to occur. Mapping The Current State: The primary aim of Current State Map is to identify the bottlenecks and to analyze them. There are 9 plates that make up one mold base.in this value stream mapping the values for C/T, C/O and Inventory time are taken jointly for all the plates. The following processes are been involved: 1. Material Receiving 2. Sizing 3. Pre Drilling 4. Radial Drilling 5. Surface Grinding 6. CNC 7. Jig Boring/Radial Drilling 8. Radial Drilling 9. Assembly Current state: Value Added Time (VAT) Non-Value Added Time(NVAT) Total Lead Time Process Cycle Efficiency (PCE) : 83 hours. : hours. : 461 hours. : VAT/Total lead time : 83/461 : 18.00%. For a lean process PCE must be greater than 25%. Hence the current state shows that the process is not a lean process. Operations Research: Operations Research (O.R.) or operational research is a discipline that deals with a wide range of problemsolving techniques and methods applied to help make better decisions. O.R. is a tool that can do a great deal to improve productivity.it employs techniques from other mathematical sciences, such as mathematical modeling, statistical analysis, and mathematical optimization, operations research arrives at optimal or near-optimal solutions to complex decision-making problems. Operations research overlaps with other disciplines, notably industrial engineering and operations management. O.R. plays an advisory role by presenting a manager or a decision-maker with a set of sound, scientifically derived alternatives. However, the final decision is always left to the human being who has knowledge that cannot be exactly quantified, and who can temper the results of the analysis to arrive at a sensible decision. There are seven sequential steps to approach O.R, they are: (1) Orientation, (2) Problem Definition, (3) Data Collection, (4) Model Formulation, (5) Solution, (6) Model Validation and Output Analysis, and (7) Implementation and Monitoring. If these steps are not given sufficient attention then O.R techniques become ineffective in the real world. Sequencing: Sequencing can be viewed as a special kind of problem commonly encountered in production shops where various types of products are to be processed over various combinations of machines. For example, let there are m jobs, each of which has to be processed one at a time, on each of n different machines. Also the time required for different machines and different jobs are given. The main objective is, to find the optimal sequence of jobs to be done using different machines in such way that the overall time required for completion of all jobs (Total Elapsed Time) must be minimum. Also the idle time (machine waiting time) of the machines must be minimized. Objective: The main objective of sequencing in this study was: To find the minimum elapsed time To find the optimal sequence for the plates to be machined

3 297 Hariram VR, et al., 2017/Advances in Natural and Applied Sciences. 11(4) April 2017, Pages: Processing N Jobs Through M Machines: The operations that are considered for sequencing are: 1) Sizing, 2) Pre Drill, 3) Radial drilling, 4) Surface Grinding, 5) CNC, 6) JB/RD, 7) Radial Drilling. The sizing operation is outsourced and takes 24 hours for all the plates to return to the industry. In this problem, there are 9 jobs and 7 machines that are involved. The first step is to check whether conditions are satisfied. STEP 1: Checking For Satisfactory Conditions Time Taken For Each Operation (In Hours) S No. Plate Sizing Pre Drill Radial Surface Radial CNC JB/RD Drill Grinding Drill V A B C D E F 1 Top Plate Stripper Plate Cavity Plate Core Plate Core Back Plate Parallel Blocks Ejector Plate Ejector Back Plate Bottom Plate Conditions: The data must satisfy either of the conditions 1) Minimum of [V] Maximum of [A/B/C/D/E]. 2) Minimum of [F] Maximum of [A/B/C/D/E]. We see that the minimum of F is 0.5 and maximum of [A/B/C/D/E] is 4. Hence condition is not satisfied. But the minimum of V is 24 and maximum of [A/B/C/D/E] is 4. Hence the condition is satisfied. Therefore we are justified to convert to two machine problem. STEP 2A: CONVERTING INTO TWO MACHINE PROBLEM X Y S.No. {V+A+B+C+D+E} {A+B+C+D+E+F} STEP 2B: Finding Optimal Sequence: i) Select the smallest processing time occurring in the list, X 1,. X 9, Y 1,.Y 9. If there is a tie, break the tie arbitrarily. ii) If the minimum processing time is X i, do the i th job first. If it is Y j do the j th job last. This decision is applicable to both machines A and B. iii) Having selected a job to be ordered, there are now n-1, jobs left to be ordered. Apply the steps i) and ii) to the reduced set of processing times obtained by deleting the two machine processing times corresponding to the job that is already assigned. iv) Continue in this manner until all jobs have been ordered. The resulting ordering will minimize the elapsed time. The Optimal Sequence: X Y STEP 3: Finding Minimum Elapsed Time And Idle Time: To find the elapsed time T, we prepare the following table for the above optimal sequence. Considered as the first operation and the in-time is taken as 24 hours.

4 298 Hariram VR, et al., 2017/Advances in Natural and Applied Sciences. 11(4) April 2017, Pages: A B C D E F IN OUT IN OUT IN OUT IN OUT IN OUT IN OUT Total time for optimal sequence = 52 HOURS (Min. Elapsed Time) Idle Time: Machine Time (Hours) A 14 B 49.5 C 43 D 29 E 51 F 47.5 Sequence Of Plates To Be Machined: ORDER PLATE I CORE PLATE [4] II CAVITY PLATE [3] III TOP PLATE [1] IV BOTTOM PLATE [9] V CORE BACK PLATE [5] VI STRIPPER PLATE [2] VII EJECTOR PLATE [7] VIII PARALLEL BLOCKS [6] IX EJECTOR BACK PLATE [8] Improvements Made: Kaizen burst- Vendor department were made to follow up on the outsourced parts and made sure that the parts arrived with proper dimensions. This was made possible by adding an extra worker into the department. Reworks have been reduced in the following machines: Radial Drilling Jig Boring Sequencing A proper sequence of jobs was suggested, accepted by the industry and being followed. Increase in productivity by reducing the lead time. Future State Map: The future state map shows the impact of the improvements made in the process. Future state Value Added Time (VAT) Non-Value Added Time(NVAT) Total Lead Time Process Cycle Efficiency (PCE) : 83 hours. : hours. : hours. : 25.20%. Current State Future State Performance Improvement Value Added Time (VAT) 83 hours. 83 hours. - Non-Value Added Time(NVAT) hours hours % Total Lead Time 461 hours hours % Process Cycle Efficiency (PCE) 18.00% %. 7.2 %

5 299 Hariram VR, et al., 2017/Advances in Natural and Applied Sciences. 11(4) April 2017, Pages: Conclusion: The Lead Time for the entire manufacturing process was reduced resulting in customer satisfaction. Since the time was reduced the overall cost of production is reduced yielding more profit for the industry. Hence by employing lean and operations research techniques the overall performance of the industry was improved. REFERENCES 1. Asefeso, A., Lean Six Sigma: (Cost Reduction Strategies). AA Global Sourcing Ltd. 2. Hansen, M.V., Cornerstones of Cost Management. 3. Hariram Vedapatti Ranganathan, M.Z., Sustainable supply chain management in automotive industry- Supplier company relationship and Integration management challenge. International Journal of Academic Conference proceeding. 4. Korakot Yuvamitra, J.L., Value Stream Mapping of Rope Manufacturing: A Case Study. International Journal of Manufacturing Engineering. 5. Rother, M. and Learning to See: Value Stream Mapping to Add Value and Eliminate Muda,. Brookline: The Lean Enterprise Institute. 6. Thomas McDonald, E.M., Utilising Simulation to Enhance Value Stream Mapping: A Manufacturing Case Application. International Journal of Logistics Research and Applications.