In apparel manufacturing (2 files merged)

Production Capacity of a factory

In Apparel Manufacturing, “Production capacity” is one of the most important criteria used for vendor selection by the buyers. It is because; the production time of an order is directly

proportional to vendor’s production capacity. So it is very important that marketing and planning personnel should aware about the production capacity of their production units.

Capacity of a factory is primarily expressed in terms of total machines factory have. Secondly,

how much pieces the factory produces on daily for the specific products? In general, total

numbers of machines in a factory mostly remains same for a period. But factory may produce

various types of product during the season. According to the product (style) category, machine

requirement may change and daily average production in each style may vary. So to be specific

during booking orders, planner should know exactly how much capacity he or she needed to

procure the order in a given time period.

FACTORY PRODUCTION CAPACITY-

Factory production capacity is derived from the resources available at the manufacturing plant. It

is calculated simply by the amount of machines available and hours per day determined to work

to be realistic, one has to determine the efficiency level of the operators and incorporate the

percentage to derive actual capacity.

Example: if a factory has 100 machines and working hours are 8 hours per day and 26 days per

month. The efficiency level of operators is observed to be at 80%. The production capacity

available time per month would be calculated as below:

Available monthly production time capacity:

100 machines x 480 Mins x 80 / 100 = 38400 Mins / day.

38400 Mins x 26 days = 998400 Mins /month or 16640 hours/month.

(Sewing Floor (Image Credit: Shahi Exports Pvt. Ltd. via Facebook page)

A factory’s capacity is presented in total minutes or hours or in pieces (production per day). The method used to calculate capacity has been explained in the following. To calculate Daily

production capacity (in pieces) one needs following information.

1. Factory capacity in hours

2. Product SAM

3. Line efficiency (Average)

1. Calculation of factory capacity (in hours): Check how

many machines factory has and how many hours’ factory runs in a day. For example suppose,

Total number of machines = 200

Shift hours per day = 10 hours

So total factory capacity (in hours) = 200*10 hours = 2000 hours

2. Calculation of Product SAM (SAM): Make a list of product category

that you manufacture and get standard minutes (SAM) of all products you make from work study

engineers. If you don’t have product SAM then calculate the SAM. Or you can use average SAM of the products. Suppose you are producing shirt and its SAM is 25 minutes.

3. Factory Average Efficiency: This data is collected from industrial

engineer. Or calculate it with historical data. Suppose average line efficiency is 50%. Read the

article - How to calculate efficiency of a production line or batch?

Calculation of production capacity (in pieces): Once you have

above information use following formula to calculate production capacity.

Production capacity (in pieces) = (Capacity in hours*60/product SAM)*line efficiency

For Example: Suppose a factory has 8 sewing lines and each line has 25 machines. Total 200

machines and working shift is 10 hours per day. Total factory capacity per day is 2000 hours

(200 machines * 10 hours). If factory is producing only one style (Shirt) of SAM 25 minutes and

used all 200 machines daily production capacity at 50%

= (2000*60/25)*50% Pieces

= (2000*60*50) / (25*100) Pieces

= 2400 Pieces

[Note: Production will vary according to the line efficiency and during learning curve or in the

initial days when style is loaded to the line]

Production (capacity) planning is normally done based on sewing capacity. Having knowledge of

the capacity in other processes (internal or external) is also very important. Otherwise planner

may fail and will not be able to meet the dead line. Other departments such as Cutting room

capacity, Finishing room capacity, Washing Capacity and capacity of the value added jobs.

EXERCISE TO UNDERSTAND RELATIONSHIP OF CAPACITY

TERMS-

Let’s say ABC Garments Company has 10 operators who work 8 hours a day. The plant has 90%

efficiency level. A customer brings in order for 6000 units of style “a” that needs to be delivered in 10 days. The plant already has a committed capacity of 300 hours for the 10 days period.

Working shift is 8 hours a day in which 1 hour is mainly for lunch and tea time breaking.

It was established that style “a” has a production time of 5 SAM. The order of 6000 units requires 30,000 SAM (500 hours). What factors should be considered in deciding whether to

accept the order or refuse?

Ankur shukla

Apparel Production Management (2-sem)

Production Technology

Resource-http://www.onlineclothingstudy.com/2011/11/how-to-calculate-production-capacity-

of.html.

Line Balancing

Introduction-

Line and work cell balancing is an effective tool to improve the throughput of

assembly lines and work cells while reducing manpower requirements and costs.

Assembly Line Balancing or simply Line Balancing (LB) is the problem of

assigning operations to workstations along an assembly line, in such a way that the

assignment be optimal in some sense. LB has been an optimization problem of

significant industrial importance: the efficiency difference between an optimal and

a sub-optimal assignment can yield economies (or waste) reaching millions of

dollars per year.

LB is a classic Operations Research (OR) optimization problem, having been

tackled by OR over several decades. Many algorithms have been proposed for the

problem. Yet despite the practical importance of the problem, and the OR efforts

that have been made to tackle it, little commercially available software is available

to help industry in optimizing their lines.

Line Balancing is leveling the workload across all processes in a cell or value

stream to remove bottlenecks and excess capacity. A constraint slows the process

down and results if waiting for downstream operations and excess capacity results

in waiting and absorption of fixed costs.

LINE BALANCING (Process Organization)-

The Line Balancing is “to design a smooth production flow by allotting processes to workers so as to allow each worker to complete the allotted workload within an

even time” It is a system where we meet the production expectations and we can find the same amount of work in process in every operation at any point in the day

How do we start balancing the production line?

Well we can start by determining how many operators for each operation are

needed for a determined level of production. After this we need to determine how

much WIP we need to anticipate production problems. Recommended WIP is 1-

hour inventory level for each operation. A good range would be from 30 min to

120 min inventory level.

Line Balancing in apparel industry-

It is the allocation of sewing machine, according to style and design of the

garments. It depends on what types of garments we have to produce. It is done to

increasing productivity.

When you consider mass production, garments are produced in lines or set of

machines instead of single machine. A line may be assembly line, modular line or

section, a line set with online finishing and packing. A line includes multiple work

stations with varied work contents. Production per hour is varied depending on

work content (standard minutes of particular task/operation), allocation of total

manpower to a particular operation, operator skill level and machine capacity.

Operation with lowest production per hour is called as bottleneck operation for that

line.

Objectives of Line Balancing

Match the production rate after all wastes have been removed to the talk time at

each process of the value stream.

1. Regular material flow.

2. Maximum uses of man power and machine capacity.

3. Minimum process time.

4. Minimizing slack time.

5. Minimizing workstation.

Maximum output at the desired time.

1. Quality maintenance of the garment.

2. Reduce production cost.

3. Importance of Line Balancing

4. Line balancing helps to know about new machine required for new style.

5. It becomes easier to distribute particular job to each operator.

6. It becomes possible to deliver goods at right time at the agreed quality for

list cost.

7. Good line balancing increase the rate of production.

8. Line balancing helps to compare the required machinery with the existing

one and compare balance.

9. It also helps in the determination of labor requirement.

10. Good balancing reduces production time.

11. Profit of a factory can be ensured by proper line balancing.

12. Proper line balancing ensured optimum production at the agreed quality.

13. It reduces faults in the finished product.

Example of Line Balancing

1. Machine layout with actual production.

>Process#1. Production 40 pieces by 1 machine end production 40 pieces.





Output: 40pices/hour.

Analysis: Insufficient production due to lack of supply.

2. Machine layout for balancing production.

Analysis: Action plan for further development.

Replace skilled or experienced operator for process#3, then production will

increase, when production will be 80pices/hour. Then same target 90pices for

process1, 3 & 4 and research on it, how production can be increased. The

following action can be done.

Limitations of Line Balancing

Production lines were designed so that conveyor belts paced the speed of the

employees‟ work. This arrangement wasn't appreciated by the employees.

Inevitable changes lead to production lines being out of balance.

Rebalancing causes disruptions to production

Ankur shukla

Apparel Production Management (2-sem)

Production Technology

Resource- Read more: http://textilelearner.blogspot.com/2013/09/line-balancing-in-apparel-

production.html#ixzz3ZqNMnEav.

Education

In apparel manufacturing (2 files merged)