This study was carried out at the Jayantha saucepan industry to improve and
enhance the productivity by reducing the idle time and enhance the bottleneck by different
methods such as changing the layouts, changing the number of work stations and changing
the process flow. During the study, it investigated and searched for possible solutions and
alternatives aimed at achieving the objective by Pareto analysis for time study, allocating the
work stations in an effective way, changing the layout for a better productivity, and
analysing skill matrix to allocate the works for the current labourers, and train the labourers
and need of hiring more labourers for the particular work stations in an efficient way to
enhance the bottleneck manually. Further improvements such as adapting into new
techniques and using better alternatives for some processes were also discussed to enhance
the productivity of the local saucepan manufacturing industry. Overall, suggested
alternatives yielded an expected improvement of 20% in the production capacity

Gayan, R.B.A.

Rameshkanna, Y.

Ratheesan, R.

English

IR South Eastern University of Sri Lanka

173 
 
PROCESS ANALYSIS AND OPTIMIZATION OF CONVENTIONAL 
SAUCEPAN MANUFACTURING INDUSTRY VIA TIME STUDY 
 
R. Ratheesan
1
, R.B.A.Gayan
2
 and Y.Rameshkanna
3 
1 Department of Mechanical Engineering, South Eastern University of Sri Lanka 
ratheesan1990@gmail.com, yrameshk26@gmail.com, ratheesan1990@gmail.com 
 
ABSTRACT: This study was carried out at the Jayantha saucepan industry to improve and 
enhance the productivity by reducing the idle time and enhance the bottleneck by different 
methods such as changing the layouts, changing the number of work stations and changing 
the process flow. During the study, it investigated and searched for possible solutions and 
alternatives aimed at achieving the objective by Pareto analysis for time study, allocating the 
work stations in an effective way, changing the layout for a better productivity, and 
analysing skill matrix to allocate the works for the current labourers, and train the labourers 
and need of hiring more labourers for the particular work stations in an efficient way to 
enhance the bottleneck manually. Further improvements such as adapting into new 
techniques and using better alternatives for some processes were also discussed to enhance 
the productivity of the local saucepan manufacturing industry. Overall, suggested 
alternatives yielded an expected improvement of 20% in the production capacity. 
 
Keywords: Productivity, Time Study, Facility Layout, Standard Time, Bottleneck 
 
 
1. INTRODUCTION 
There are several methods to manufacture an aluminium (Al) saucepan such as die-casting, 
spinning, non- stick cookware making. Developing countries like Sri Lanka uses the sand 
casting method which is one of the simplest and cheapest way to produce aluminium 
cookware. It doesn’t contain any complicated processes; first they melt al, then cast it and 
polish it for a better surface finish. Even though this method is widely used in Sri Lanka 
unfortunately there are no any standards in operation to specify and improve the process. 
There are many problems associated with the current local saucepan making industry such as 
improper layout, inefficient use of labours, lack of technology usage, and idle time of the 
work stations. The proper process optimization is needed to enhance the productivity of the 
process.. Many researchers have worked on the quality improvement of the casting and the 
finishing operation, but not on process optimization. Therefore one of the major saucepan 
production companies in Sri Lanka, “Jayantha aluminium industry (JAI)” was selected as a 
case study to investigate issues prevailing in the saucepan manufacturing industry. This 
paperpresents the findings of the case study. The paper is organized as follows. Next section 
describes the saucepan manufacturing process of jai. In the section iii problem definition and 
research aim is described. Section IV of the paper described the followed methodology for 
time study. Section v describe the factors consider when improvements are made. Section VI 
and vii discussed the conclusion of the research. 
 
Process Description 
Saucepan manufacturing is done with several different operations in a sequence. These 
operations are listed down below. 
1. Al is melted in a furnace. 
2. Sand mould is made 
3. Pour melted Al into the mould and make casting 
4. Break the mould and removing the casting 
5. Removing burr and smoothen the sharp edges 
174 
 
6. Polishing inner surface 
7. Remove sprue 
8. Polishing outer surface 
9. Making and fixing handle 
 
 
No standard time for activities -Therefore workers cannot be evaluated according to their 
performance.  
 
Bottlenecks in the production process - More time has been taken by the mould 
preparation and polishing inner surface. Apart from that, to polish the outer surface, remove 
sharp edges and making the handle takes considerable amount of time compared to other 
operation. Because of these time differences between each operation, more bottleneck points 
could be found. 
 
Quality Variation ofthe Product - Most of the production processes are being done 
manually by the workers. Among these processes, polishing inner surface, polishing outer 
surface and mould preparation are required high skill level, because the skill level directly 
affect the production rate and the product quality. 
2. METHODOLOGY 
Time study is conducted to eliminate bottlenecks and standardised process time. 
Following steps were employed to conduct a time study. 
 
1. Normal time for each operation was measured and the standard time was calculated 
for each operation. 
2. Bottleneck points were investigated and checked. 
3. The required number of observations to predict the true time within ±10%    
precision and 95% confidence level was obtained using the following formula: [1]-
[3] 
 
SD= √ (x- x̅) 2/n 
 
  
Where, 
X= each stop watch reading or individual observation 
Σ= sum of individual readings 
n= required number of observations/sample size 
E = margin of error 
 
4. The standard time for each inspection point was calculated by using the   following 
formula [4] 
 
Standard time= Normal time*100/ (100-allowance in percent)  
5. Analysis charts were used to understand the bottleneck points. 
6. The bottleneck points were subdivided into more elements and the normal time 
 was measured for each element. Steps 2 and 3 were repeated for each 
element. 
7. Further investigation and analysis were done for the most time demanding elements 
inthe bottleneck 
8. Possible solutions and alternatives were searched and evaluated by using principles 
of motion economy and appropriate tools from motion and time study and 
ergonomics. 
175 
 
3. RESULTS AND DISCUSSION  
a. Sample Size, Normal Time and Standard Time. 
In this study, manufacturing process is divided into sub processes and mean time 
taken to each process is measured. Mean time is measured to 95% percentile 
confidence. Initially a sample of 40 observations is used to calculate the required 
sample size to meet the above condition. It was found that, 79 observations should 
be done in order to find mean time for mould preparation with 95 percentile 
confidence. Same method is used to estimate the sample size for all sub process and 
mean time for each process is measured. Mean time does not contain allowances. It 
is the actual time taken for each process if average worker work at normal tempo. 
However it is not expected for a worker to work in the same tempo throughout the 
day. The operator may take time out for personal needs, which is beyond the control 
of them. For working 8h/day, moderate workers might have 5% - 8% unorganized 
time for their rest [4]. Since in this cookware manufacturing industry, workers has to 
work hard, 7% allowances is allocated. Accordingly, the standard time for each 
process is found. These standard times are mention in table 1. More time is taken for 
mould preparation, polishing inner surface, remove sharp edges, handle making, 
polishing outer surface respectively. There is a possibility to reduce time taken for 
these processes. All though Al melting process takes more time, it was not analysed 
since melting procedure and melting time were fixed by the manufacture. 
 
Table I. Standard Time Measurement 
 
Steps Normal 
Time (Sec) 
Standard Time 
(7% Allowance) 
MeltingAl 1.5 hrs. - 
Sand Preparation 25.0 27 
Mould Preparation 140.0 151 
Poring Al 3.7 4 
Break the Mould 4.2 5 
Collecting castings 1.4 2 
Removing Sharp edges 29.0 31 
Polishing inner surface 73.1 79 
Polishing outer surface 25.4 27 
Sprue Cutting 8.4 9 
Handle Making 4.8 5 
 
b. The Process Flow Diagram 
Actually melting is done at the beginning of each working day while other processes 
are continuing .process flow diagram of current process is illustrated in Figure1. The 
whole process is divided into two main categories. That are finishing and casting. 
176 
 
Process times for each process in finishing area and casting area are mentioned in 
Table 2 and Table 4 respectively. In this time study casting and finishing processes 
are considered as two separated batch processes. Therefore a time study analysing 
has been done separately for these two processes. 
 
 
 
Figure 1. Process Flow Diagram 
 
c. The Allocation Work Station 
The production is a batch process, where initially the casting will be done and after 
that the finishing operation is done batch wise. Therefore, analysing the time of 
whole process in a single view is not possible. Hence it was decided to analyse in 
two different parts. In the current flow there is a huge bottleneck at the inner surface 
polishing. In order to avoid the idle time of the each work station, re arrangement of 
the process flow and parallel allocation of workstations were needed. 
 
Table 2. Average Time Consumption of the PolishingProcess 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 2: Work station allocation 
 
 
In order to avoid the idle of the sprue cutting, the number of inner polishing work stations 
should be increased to 9, which is not possible because of the insufficient floor area and the 
labour force. With the existing floor area and the labour, the arrangement of the workstation 
could be liked in Figure 2. 
Process Time (sec) 
 
Remove sharp edges 26.9 
Polish inner surface 73.1 
Polish outer surface 25.4 
Sprue remove 8.3 
Handle making 29 
Melt 
Al 
Pour molten 
A1 into mould 
Solidify Break the 
mould 
Remove 
sharp edges 
Polish inner 
surface 
Polish outer 
surface 
Cut the 
sprue 
Fix 
handle 
Make sand 
mould 
177 
 
From this arrangement, the number of inner polishing stations have been increased to reduce 
the idle of the all workstations. Table 3, demonstrate the variation of ideal time with respect 
to number of inner surface finishing stations. 
 
Possibilities of the above arrangement – in order to allocate the workstations, the number of 
labourers and the skills of them were considered. Allocating three workers for inner surface 
polishing has reduced the idle time of other workers drastically.There is enough space to 
allocate 3 inner polishing stations and company has some facilities to install if 9 inner 
polishing stations are installed the idle times of other working stations are reduced 
significantly. But there are not sufficient facilities and labourers to allocate aforementioned 
amount of resources. The production rate is not affected with the above processes when 
compared with the polishing processes. Therefore the only improvement that can be done to 
increase the productivity with the above processes is increasing the number of workers 
involved with pouring and breaking the moulds. Also the current time taken to polish the 
saucepan in significantly larger than the above processes where, there are more moulds left 
to be polished for the polisher after a casting process. 
 
Table 3. Average Time Consumption ofthe CastingProcess 
 
Process Time (Sec) 
Al melting 1.5 hour 
Mould preparation 36 
Pouring 3.7 
Breaking the mould and take out cast 2.6 
 
d. Pareto Analysis for Time Study 
Since finishing process has a sequence of operations, Pareto analysis was done in 
order to identify the most critical processes which takes longer production time. 
From this analysis it was found that polishing inner surface, removing sharp edges, 
handle joining and polishing outer surface take89% time from the total production 
time. Therefore improvements for the production process has been done for these 
process. In the casting process, mould preparation takes 83% of time from the 
casting process. Therefore improvements for the casting process is only been done in 
the mould preparation. 
 
e.  Flow Chart 
Material flow chart can be used to reduce the material handling in the factory by the 
analysing it. Plan layout with the material flow is sketched in the below figure 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 3: Existing Facility Layout 
178 
 
 
Lines drawn on the sketch to demonstrate the material movement in the factory. High 
amount of material handling is leading to increase the production cost and lower the 
production rate [5]. Therefore new layout is introduced in order to minimize the material 
handling. 
All the production processes are currently done in 2646ft2 (42ft × 63ft) area (figure 4) 
excluding handle making and handle fitting processes. Since the factory area is limited all 
the modifications had to be done in this 2046ft2 area. The modifications are done in the way 
of minimize the weight into distance. At the same time, new lay out has been introduced to 
reduce work in- progress inventory and throughput time, improve the work satisfaction by 
increasing the safety of material handling and minimizing the material handling path 
intersections. Optimized facility layout is obtained through the systematic layout planning 
(SLP) [6]. It derives from information such as flow of material between the different 
workstations their adjacency requirements and the corresponding reasons. From the 
relationship chart (Figure 4), relationship diagram and facility layout (Figure 5) were 
developed respectively. Activity relationship chart is developed considering the material 
movements across the workstations. In this chart, denotation “A” used if material movement 
is absolutely necessary between those two workstations and denotation “E”, “I”, “O” and 
“U” used if material movement between workstations are especially important, important, 
ordinary, unimportant and undesirable respectively. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 4. Activity Relationship Chart 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 5.  Relationship Diagram and Proposed Layout 
179 
 
 
From the proposed layout, workstations which are having more material movements were 
place closely. Large size saucepan moulds are required more molten Al than the small sizes. 
Therefore pouring cups have to be refilled frequently. Therefore workers have to go to the 
furnace more frequently when filling bigger saucepan moulds. In order to reduce the 
traveling distance of the workers, large moulds are suggested to place near the furnace. 
In this research, workers travelling with material and traveling without material were 
compared separately. 
 
f. Detailed Process Study for Bottlenecks 
Time study results have exposed the bottleneck in the mould preparation. It is the 
most time taken process in the cast saucepan manufacturing process. Therefore detail 
analysis has been done to optimise the production process. From the detailed time 
study, possible improvements were identified. They were listed down below. These 
improvements would increase the productivity and workers satisfaction. 
 
g. Further Improvements and Possible Solution to Improve the Productivity. 
 Introduce electrical wrench to tighten wise and chuck. 
 Proposed new layout to reduce material handling.  
 Specialisation of workers in their respective operations 
 Introduce parallel work stations to minimize bottlenecks 
 Place two patterns once instead of placing preparation introduce finishing 
machine to enhance the quality of the product and the safety of the workers. 
 
h. Tightening Chuck And Wise 
At present chuck and mechanical wise are used to clamp the pasted saucepan. Each   
and every saucepan is needed to clamp three times in its production process. In the 
process of smoothing sharp edges, it takes 55% (6.2 out of 11.2) of time duration to 
loosing and tightening. In polishing outer surface and inner surface, it is 30% (8.1 
out of 25.4) and 18% (14.3 out of 81.2) respectively. The tightening torque is also 
not consistent since the tightening is done manually by the workers. Sometimes 
workers have to retighten the wise and chuck if they were not tight enough to bare 
external forces. If it is over tightening, extra time and effort be put to lose it. These 
difficulties can be eliminated by introducing electric chuck and pneumatic clamps. It 
can be used to clamp and unclamp the wise and chucks quickly. In other hand, it 
always gives a constant torque which is useful to eliminate the problem associate 
with over tightening and under tightening. However, high capital is required to 
replace existing clamps and chucks. Since this analysis were done for the small scale 
saucepan manufacturing industry, mostly focus on low cost solutions. Instead of 
replacing existing wises and chucks, electric wrench or pneumatic wrench can be 
used to tighten and loosed the existing wises and chucks. Though this is a low cost 
solution, it gives the same advantages as electric chucks. Therefore it is more 
suitable to use electric wrench. 
 
i. Separate The Finishing Inner And Outer Finishing Process For Two Sections 
[7]. 
Finishing inner and outer surface is currently done by a single worker. Its take much 
time to setting up the same polishing machine from inner polishing to outer 
polishing. These setting up time could be reduce by using separate stations for inner 
and outer finishing process. On other hand, letting a people to do a one work would 
be increased the productivity due to specialization. Both specialization and reducing 
setting up time would be lead to increase the productivity of the factory. 
 
 
180 
 
4. CONCLUSION  
The time study was carried out in Jayantha aluminium industry with more than eighty 
samples. 
The time samples were taken in different times during a week with a 0.01 seconds significant 
stop watch. Measurements were taken in morning, evening and throughout a week. The 
experimental value of time samples were analysed and bottleneck point was investigated and 
checked. The required number of observations to predict the true time within ±10% precision 
and 95% confidence level was obtained using the following formula:  
 
Standard time= Normal time*100/ (100-allowance in percent) 
From this method it was found the major time consuming are and proposed some techniques 
to reduce the cycle time such as use proper tool to fill sand into the mould, place two pattern 
once instead of placing patterns one by one and improving the tightening the chuck. From 
those methods it is expected to have a 5-10% of time reduction. There are some specific 
ways to improve the productivity. The better layout selection with elimination of waste 
material movement and time. Also a better flow method to reduce the idle time and avoid the 
bottleneck in each working stations were also suggested. This investigation found the best 
work station allocation from this the total idle time was reduced from 203 seconds to 31.1 
seconds. There was a huge wastage of time in manual polishing method and to avoid that it 
was suggested to design and fabricate a simple polishing machine to reduce the cycle time. 
5. REFERENCES  
 [1] Al-Saleh,K.S.(2011) Productivity Improvement Of A Motor Vehicle Inspection Station 
Using   Motion And Time Study Techniques, J. King Saud Univ. - Eng. Sci., Vol. 23, 
No. 1, Pp. 33–41 
[2] Triola, M.F  (2012) Elementary Statistics,. Boston: Pearson. 12 Edition 
[3] Garrett,S. K.,Gramopadhye,A. K&Melloy, B.J.(2001) The Effects Of Per-Lot And Per-
Item Pacing On Inspection Performance. Int. J. Ind. Ergon., Vol. 27, No. 5, Pp. 291–302. 
[4] Barnes,R.M (1980) Motion and Time Study: Design and Measurement of Work. 7 
Edition. New York. 
[5] Filippo, D., Maria, A., Borgia, O., &Tucci. M. (2013) Layout Design fora Low Capacity 
Manufacturing Line: A Case Study.International Journal of Engineering Business 
Management. Pp - 5772/56883. 
[6] Chandrashekar. D. (2007) Facility Planning and Layout Design. Technical Publications. 
[7] Karasu,M.K., Cakmakci, M. Cakiroglu,M. B.,Ayva,E. &Ortabas,N. (2014) Improvement 
of Changeover Times via Taguchi Empowered Smed/Case Study on Injection Molding 
Production Measurement, Vol. 47, Pp. 741–74 
 
 
 
 
 
 
 
 


Process analysis and optimization of conventional saucepan manufacturing industry via time study

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Process analysis and optimization of conventional saucepan manufacturing industry via time study

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