TOPIC - Efficient Utilization of Employees in the Garment Industry using
Operations Research.
INTRODUCTION
Proper utilization
of manpower determines the efficiency of a system. The aim is to determine a
mechanism for the garment industry to utilize the manpower with highest
efficiency. In a garment industry, the study was done to determine the proper
mechanism for assigning employees different operations in the sewing section.
The scope is
restricted to sewing section due to following considerations-:
(A)
Complex
combinations of operation are done by large number of workers.
(B)
Cost of
production mainly depend on this section.
SITUATION ANALYSIS
(A)
Current
efficiency of employees is 50% and there is a large scope in improvement.
(B)
Selling
price of the product is beyond the control of the company due to competition in
garment industry.
(C)
There
are 450 employees in sewing section which are grouped into 18 teams having
approx. 25 employees.
(D)
Teams
have number of employees according to the complexity of work.
(E)
Each
employee work for 10.5 hours a day and there is 5% absenteeism on an average.
(F)
After
getting the cut pieces each employee is given proper instructions and the
required tools.
(G)
Time
is analyzed by considering sewing time, time for handling tools, arranging and
idle time which occur due to delay by previous employee.
(H)
Company
currently uses GSD for average time allocation for each operation.
(I)
The
experienced staffs assign operations to the employees which is a problem in
reaching high efficiency.
CONSTRUCTION OF MODEL
The decision variables used in the
mathematical model of
assignment,
are defined as follows:
Xij
= 1 if employee i performs task j 2
0 otherwise
tij is the time taken
by the ith employee to perform the jth
task.
Then
the objective function ΣΣt ijxij denotes
the total
time required to
produce a single product from the style.
Σxij
=1 for all j = 1,2,…n 3
Σ xij
=1 for all i = 1,2,…m 4
Equation
(3) states that each task to be performed by exactly
one
employee and (4) states each employee is to perform
exactly one task
To minimize this
two modifications are done.
(a) the concepts of integer programming have
been integrated with the model in order to choose between the best set of
employees
Σxij
=1 for all j = 1,2,…n
Σ xij
=1 for all i = 1,2,…m
Σ
Xij = n
(b) It is assumed that more than one employee
can be assigned to a single task. Let αj be the number of employees assigned to task j.
Accordingly
the final version of the model would read as
Follows
Minimize ΣΣt ijxij
subject
to Σ Xij = α
SOLVING THE MODEL USING MICROSOFT EXCEL
The
wok book has been designed with a capacity to include 50 employees and 33 tasks
generating 1650(=50x33) variables. The high capacity requirement of the model generated can’t be
solved by using the inbuilt Excel Solver. Due to this reason an Excel add-in is
used to replace the Excel Solver. the generated Excel workbook requires no technical work to be
done by the user. It is recommended to keep a separate workbook for each team.
However the maximum number of employees that can be entered into the workbook
is 50, which is around twice the number of employees that is usually allocated
into a team. This has enabled the company to keep additional records of
important employees. These additional records can be used to evaluate the team
with different combinations of employees which can be used for efficient
employee transitions between teams. The first sheet of the workbook is named
“Timing”. This includes previous timing records of each and every employee in
respect of styles. These timing records are obtained by calculating the time
taken by a particular employee to perform a particular operation per unit of
SMV In the next worksheet the final model is presented in the form of two
matrices. The first matrix provides the time taken by each and every employee
to complete each task defined. The second matrix contains binary values which
indicate whether a given employee is assigned for a given task or not.
Whenever
the user enters the details of the style to the workbook, the default values of
the two matrices are automatically calculated
RESULTS
The
efficiency of the company is calculated by the formula
E =( (n × TSMV
) / 60
)/PH
(13)
Where
E: Efficiency
n: Number of units produced within
the day
TSMV: Total SMV of the style
PH: Production hours of the day.
The
efficiency has increased dramatically due to application of the model developed
by this study and reached to 80%. This improvement was mainly achieved by minimizing the
bottlenecks by the optimal allocation of the employees.
CONCLUSION
This
improvement was mainly achieved by minimizing the bottlenecks by the optimal allocation
of the employees. The goal
was successfully achieved by using the linear programming algorithm.