IMPROVEMENT OF PRODUCTIVITY BY APPLICATION OF BASIC SEVEN QUALITY

International Journal of Advance Research in Engineering, Science & Technology ISSN No:Applied

Improvement of Productivity by application of Basic seven Quality control Tools in manufacturing industry Chiragkumar S. Chauhan1, Sanjay C. Shah2, Shrikant P. Bhatagalikar3 1

M.E. (Industrial Engg.)Student, 2Professor, 3Sr.Quality Head Department of Mechanical Engineering, 3Quality assurance Department 1,2 G. H. Patel College of Engineering & Technology GTU, V.V.Nagar, Gujarat, India, 3ABC BEARING Ltd., Bharuch, Gujarat, India 1,2

Abstract This project basically deals with to improve quality of tapper roller bearing by applying some of the seven Quality control tools, To Improve the production of manufacturing flow line – BWF-01 by reducing percentage of Rejection & Rework. Sum of the prominent problems which are face in the bearing company. The aim of the research was to show on practical examples that there is real possibility of application of 7QC tools. Conducted research has shown that there is possibility of systematic application of all of the 7QC tools in the frame of companies’ overall quality management system. The paper is dedicated to present basic concepts to show how the basic quality tools can be used to solve problems and improve quality. Finally, a personal contribution in the area of quality tools is presented. Keywords: PDCA, 7QC tools, Improvement Processes I. INTRODUCTION Quality Assurance is a method of managing all the activities that affect the quality of product/service. Ensuring that a given system will provide assurance of the quality of the output from that system. It is about managing to achieve quality and prevent defects. Quality concepts have changed over time. Quality of product means the product must be within the acceptable limits. Edwards Deming, explained chain reaction in his book “out of the crisis” published in 1986. The benefits from quality and process improvements to organization are: a. Improved Quality b. Less rework, fewer mistakes and hence cost decreased c. Capture the market with better quality and lower price d. Improved Business e. Improved productivity [1] The seven quality control tools are: 1) Flow chart 2) Cause-and-Effect diagram 3) Check sheet 4) Pareto diagram 5) Histogram 6) Scatter plot 7) Control charts In successful application of quality tools the implemented quality management system is advantage. The quality management principles are starting point for company’s management striving for continuous efficiency improvement in long period of time and customer satisfaction.

Fig 1. Seven quality tools (7QC tools) for quality improvement[3] II .PDCA CYCLE: The most common process of continuous improvement is the PDCA Cycle, which was first developed by Walter Shewhart in the 1920s, and promoted effectively from the 1950s by quality guru Dr Edwards Deming, as a strategy to achieve breakthrough improvements in processes. The four steps in the cycle which is also known as the Deming Wheel.

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Fig 2. PDCA CYCLE The cause of inefficiency and poor quality is the system, not the employees and it is management’s responsibility to correct the system in order to achieve desired results. Continuous improvement process is based on application of Deming’s quality cycle or PDCA-cycle, shown on Fig. The PDCA-cycle is integral part of process management and is designed to be used as dynamic model. The completion of one turn of cycle flows into the beginning of the next. Main purpose of PDCA-cycle application is in process improvement. When the process improvement starts with careful planning it results in corrective and preventive actions, supported by appropriate quality assurance tools, which leads to true process improvement.[5] Four Phases of PDCA Cycle • Plan:a change aimed at improvement • Do: Carry out the change • Check:Study the results • Act: Adopt, adapt, or abandon

2.Analyze Current Situation. 3.Identify Root Causes 4.Generate and Choose Solutions Do: 5.Map Out and Implement a Trial Run. 6. Map out a trial run 7. Implement trial run Check: 8. Analyze the Results 9.Collect and evaluate results 10.Draw Conclusions. Act: 11.Adopt, Adapt, or Abandon the Intervention. The completion of one cycle continues with the beginning of the next. A PDCA-cycle consists of four consecutive steps or phases, as follows: • Plan - analysis of what needs to be improved by taking into consideration areas that hold opportunities for change. Decision on what should be changed. • Do - implementation of the changes that are decided on in the Plan step. • Check - Control and measurement of processes and products in accordance to changes made in previous steps and in accordance with policy, goals and requirements on products. Report on results. • Act - Adoption or reaction to the changes or running the PDCA-cycle through again. Keeping improvement on-going. III. DATA COLLECTION & ANALYSIS : The data collected the data over Machine wise Rejection For the Month Of AUG ' 2013 in Figure 1 Histogram:

Rejection Qty

“It would be better if everyone would work together as a system, with the aim for everybody to win.” W Edwards deming

Machine Wise Rejaction July '2013 1200 700 200

Machine Name Fig 4. m/c rejection in histogram diagram REMARK: show fig.3 machine wise rejection in highly reject quantity in BFW – 01 line, BWF- 03, etc in grinding stage Pareto analysis:

Fig 3.PDCA Cycle Methodology Plan: 1.Select Improvement Opportunity.



Fig 5. pareto analysis Cause& effect diagram:

Tapered roller bearings are separable roller bearings. The tapered rollers are guided in tapered raceways. The roller set is retained by the cage, to the inner ring (cone) between guide flange and locating flange. The outer ring (cup) is loose. Tapered roller bearings equally support radial and axial loads. BWF LINE The manufacturing processes at ABC are of paramount importance. The state of the art technologies established in the processes, generate world-class quality. The NC / CNC grinding lines from world renowned manufacturers like BWFGermany, Famir - Italy equipped with Pokayoke techniques, process & post process gauging, logarithmic crowning units, ensure consistent quality and high productivity BORE GRINDING Bore is the inner hollow portion of the ring, fitting with rotating shaft. With the help of CNC grinder bore diameter is to be maintained. BORE ROUNDNESS Roundness is determined from the difference between the radial of the incised and circum gained circle , both of which the centric of the center obtained by each calculation method. BORE GRINDING REJECTION PARAMETERS: Track size variation Due to dressing problem bore scarp(+ve/-ve) Due to loading unloading problem Sliding problem Material problem Bore gauge problem Bore step ovality (sound test) Bore roundness ACTION PLAN: Table .1 action plan for bore grinding rejection Action plan in process 1) Bore roundne ss

Causes • •

Fig 6. Cause & Effect diagram Based on information in Figure 1 a Pareto chart was constructed to identify the most common defect as shown in Figure 2. The chart revealed that bore size variation(bore grinding) is the highest defect with average of 48.8%, Odi size variation with average of 26.0%, and followed by track size variation with average of13.1 %. All other minor defects are also shown in the Pareto chart. Only the top three major defects are chosen for this case study. show the fishbone diagram for the top three defects. The root causes of these three defects can be grouped into machine, method, personal and material. IV. IMPROVEMENT ACTION PLAN TAPERED ROLLER BEARINGS (TRB).

• •

•

Corrective action Imprope r shoe setting Driver face run –out /driver worn out Worn out shoe Imbalan ce in grinding wheel Incorrec t process paramet ers

 

   

Carry out shoe setting Replace worn out driver & carry out driver grinding. Replace shoe Check for static balancing of wheel Check & correct process parameter. Rectify roundness in track grinding segregate the more roundness track from further processing.



•

3) bore step ovality

• •



In process gauge malfunc tioning Excessi ve size variatio n in track grinding





Incorrec t wheel width Incorrec t setting of wheel table position



Inform electrical maintence for rectification of cause of replacement of gauge Rectify excessive size variation in track grinding Select wheel width such that it curves the entire bore width Set the wheel table position such that entire bore width is curved in grinding.

Table .2 Data collection for bwf-01line (TRB) Job name

32011 X 33010 344/33 2 603049 3585EP 501349

Total productio n

Inner (bore)

ring

Outer ring (odi)

Total rejectio n

8958

Bor e size 67

Trac k size 2

Odi siz e 48

Trac k size 21

138

20 2884

0 27

0 1

0 29

0 19

0 76

6516 5745 9437 33560

26 23 29 172

2 1 2 8

37 34 39 187

22 19 26 107

87 77 96 474

Pareto Chart of defect 500

100

400

80

300

60

200

40

100

20

0 defect rejection Percent Cum %

odi size 187 39.5 39.5

bore size 172 36.4 75.9

trach size(or ) 107 22.6 98.5

Percent

•

rejection

2) BORE SIZE ±

0

Other 7 1.5 100.0

Fig 7. Grinding rejection in bwf-01 line . V. RESULT ANALYSIS The Histogram was also constructed to analyze the maximum defect and help determine how to yield further improvement Table shows that increased the productivity & reduce the rejection in bore grinding in bwf-01 After implementing the action plans for the top three defects, significant improvement was observed. This observation is done for two months after implementation. The Pareto chart in Figure shows that monthly defect had reduced from 48.8% in December to 36.4% in January & also reduce the inner track size variation from 12.2% in December to 1.5% in January. Company should be more disciplined and all operators must go through some simple training especially on how to handle parts to avoid defect caused by human handling. for example bore roundness , bore size variation and track size. New operator must be trained to handle the process properly. Work instruction sheets can be used as a guide for the proper work method. machine operator must check the machine condition for every shift to confirm that the machines are in good condition. REFERENCES [1]. Mohamed Aichouni, “On the use of the basic quality tools for the improvement of the construction industry: A case study of a ready mixed concrete production process”, International Journal of Civil & Environmental Engineeing IJCEE-IJENS Vol: 12 No: 05, 2012 [2].Samadhan D. Bhosale, S.C.Shilwant, S.R. Patil “ Quality improvement in manufacturing processes using SQC tools”International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 3, Issue 3, May-Jun 2013, pp.832-837 832 |


International Journal of Advance Research in Engineering, Science & Technology ISSN No:Applied [3].Mirko Soković - Jelena Jovanović - Zdravko Krivokapić Aleksandar Vujović“Basic Quality Tools in Continuous Improvement Process” Journal of Mechanical Engineering 55(2009) [4]. Juan Jos!e Tar!ı*, Vicente Sabater “Quality tools and techniques: Are they necessary for quality management” Int. J. Production Economics 92 (2004) 267–280 [5] Samadhan D. Bhosale, S.C.Shilwant, S.R. Patil “Quality improvement in manufacturing processes using SQC tools” International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 [6]. Juran’s quality planning & analysis for enterprise quality, Frank M. Gryna, Richard C.H chua, josheph A.Defeo, Tata McGraw Hill Edition

[7]Quality Control Handbook, J. M. Juran& F. M. Gryna, Prentice Hall Publications. [8] Keller.,P. Six Sigma Demystified – a selfteaching guide, McGraw-Hill, New York, 2005. [9] Pimblott. J.G. Management improvement -where to start, Quality forum, Vol. 16, No. 4,December 1990, pp. 165-173. [10]Total Quality Management by K C Arora, S K Kataria& Sons [11]Total Quality Management – Dr. S. Kumar, Laxmi Publication Pvt. Ltd. [12]. All About Six Sigma, Warren Brussee, Tata McGraw Hill Edition.

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IMPROVEMENT OF PRODUCTIVITY BY APPLICATION OF BASIC SEVEN QUALITY

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