A lot has been written and discussed about various manufacturing systems in the Apparel Industry. Different experts have different opinions on advantages and disadvantages of one system against the other. But most of the time we neglect to cover all aspects of the system when analyzing, and thus are unable to realize or visualize the actual comprehensive picture, before implementing the change in the manufacturing set-up. In fact, many times decisions are taken without even a proper analysis of various options resulting in big disasters.
Manoj Tiwari, Asst. Professor, Dept. of Fashion Technology, NIFT, Gandhinagar, shares his experience garnered while working in both Assembly Line and Modular Manufacturing System in Vogue-Velocity International, Egypt, Textrade International DRDO and LNJ Group India, to provide a guideline to adopt when opting for a suitable manufacturing system for the plant.
To initially set up a garment manufacturing unit, investment in three critical areas is required. They are: Man, Machinery, Space.
The ultimate objective of any business is to have the best utilization of above three factors, so that profits can be maximized. Since margins are shrinking in the garment industry the profitability of a company is dependent on needle movement – consistency of running machines, and to ensure smooth operations money has to be invested on worker training, automation, attachments and folders to increase productivity, and appropriate space required where both men and material can move unobstructed and systematic.
|Type of Manpower required||Salary/Month (Indian Rs.)*||Requirement for Assembly Line (Nos.)||Requirement for Modular System (Nos.)||Cost/Month (Indian Rs.) for Assembly Line||Cost/Month (Indian Rs.) for Modular System|
Further, to achieve the competitive edge companies are using various manufacturing systems like make through, conventional bundling, progressive bundling, flexible production, unit production system or the modular manufacturing system.
In the Lean Thinking, experts advocate the benefits of modular manufacturing for maximum efficiencies.
Converting a set-up from Assembly Line to Modular System or vice versa may require a good deep thought or brain storming considering all the aspects should be done before decision making. There must be no compromise with fundamentals; otherwise blind follow-up of modules may come up with bigger disasters
Modular manufacturing is a type of flexible manufacturing system, which provides faster and efficient throughput and better balancing of work by keeping lower WIP and requiring less space. The modular system enhances multi-skill development of operators, which helps in quick response to style change with achieving quality standards. Besides, it increases team spirit which helps organization in improving work environment.
Modular manufacturing groups operate in teams, or modules. The team works on one or a few garments at a time instead of a bundle of garments. The operators stand/sit at their stations and rotate to different machines as they work, becoming familiar with multiple steps in producing the garment. They also simultaneously inspect their team’s own work, catching and correcting mistakes as soon as they happen. Early experiments with modular manufacturing show that besides inspiring teamwork and improving morale, it also enhances quality and reduces worker turnover. While making a garment using modular manufacturing or the unit production, the throughput time is reduced. But then how assembly line system compares itself to the modular system.
[For comparison and calculations the product taken is 5-Pocket Denim Jean, Assumed SAM-14.0 min./garment].
Considering a shift of 8 hours per day, total available minutes per shift will be 480. SAM given is 14 minutes, which includes – time for ironing, quality check and trimming activities.
Production Calculation for Assembly Line
So, as per the above table (Figure 1), manpower required for assembly line will be = 50 (Considering sewing operators, iron man, quality checkers and trimmers only)
Expected output per shift
@ 65% efficiency
= (50 X 480) X 0.65/14
= 1114 units/shift
Total labour productivity (assembly line)
= 1114/63 (Total number of the operators)
= 17.68 units/person/shift
Production Calculation for Modular System
Expected output per shift
@ 65% efficiency
= (21 X 480) X 0.65/14.0
= 468 units/shift
Total labour productivity (modular system)
= 21.27 units/person/shift
Cost & Expense for Assembly Line
Expenditure on wages/day (assuming an average of 30 days in one month) for assembly line – 331000/30
= INR. 11033/day.
= INR. 9.9039/garment
Cost & Expense for Modular Systems
Expenditure on wages/day (assuming average 30 days in one month) for modular system – 133000/30
= INR. 4433/day
Cost/garment for modular system
= INR. 9.4729/garment
Gain/garment by using modular system over assembly line
= INR. 0.4309/garment
Prima facie opting modular system over assembly lines seems a good deal, but it does have its own bottlenecks as Mark Twain said – “There are three types of lies – LIES, DAMN LIES and STATISTICS”.
The same may happen here also, as we have not covered some crucial factors, which may directly or indirectly affect this statistical figure.
1. Machine usage vs. Idle Machine cost – In a modular system machine to man ratio is always kept more than 1, so that the multi-skilling can be utilized efficiently. It means there are always some machines idle at any given point of time. Generally for a 5-pocket jean modular set-up, we use 25 machines over 20 sewing operators; hence 20% of the total machines are always kept idle.
Keeping the sewing machine idle is definitely a cost, and it shows somewhere we are not properly utilizing the available costly resources, if we calculate straight, by working with 8 modules for a 5-pocket jean , we are using (unknowingly) 40 extra machines, by which you can successfully run an assembly line.
The another important point, in case there are small orders of different styles (For example: One style having asymmetric back), in this case clubbing of machines is not possible due to frequent change in machine settings and we have to go for separate machines for each module.
Assigning/allocating 2 different separate machines for individual modules is a costly affair and at the same time machines are not fully utilized referring to their capacity.
This is a well known fact that operator’s training and making them multi-skilled takes a good amount of time, resources in terms of money and manpower as well as managements patience also. But most of the times we skip this point taking as a secondary priority
2. Consistency in the Sewn Product quality level – Believing in the modular manufacturing concept for garments, the quality of sewn product has to be ensured by the modular team itself, there is NO quality check as each operator is responsible for checking and rectification in the product (if required), there is provisions for audits only, once output is done.
In this scenario when there is production pressure, operator misses to check the quality (uncut threads, wrong sewing margins, unmatched notches, and wrong parts attachment is very common problems). As there is only final audit in modular system, till the time you come to know about poor quality of the product, a big loss of time, material and money has already been done, which results in cost of poor quality. Producing and making things wrong are bigger losses than less/no production.
3. Consistency in daily production – Assuming that on a day 1, a modular operator, who is trained for 3 operations is absent. Unfortunately if he is a crucial operator expert in inseams or waist band attach, the production and productivity of that day for that module is in serious danger.
In a country like India, where festive seasons, health issues and climatic calamities are very often, this scenario of key operator’s absent is very normal. Here as a replacement you are left with two options – either use a multi-skilled operator from somewhere else or use three different operators for these operations – both the solutions are going to add extra cost to the process with no guarantee of achieving required quality level. At the same time if the operator is absent in assembly line, you have to deal with only one operator, who does only one operation and finding out a replacement for it, is not too different.
4. Space Utilization – In general practice for a 5-pocket jean, the space consumed by 2 modules is equal to 1 assembly line. Apart from it, we have to provide space for sewing preparatory for individual module and space for the non-productive or idle machines in the module.
It has been observed that on an average a module takes 2 years to get matured, till that time one has to compromise with daily average production of 250-300 pcs/day (against 468 units/day as calculated above @ 65% efficiency) and in the same conditions a line starts producing output average 1100 units/day (as calculated above) from 8th or 9th day of the line starts.
It means from a space of 2 modules, the factory will get approximately average 500-600 units/day output, which is equivalent to a space of a line, whereas a line can easily give 1100 units/day.
Hence it’s clear that, to get equivalent output to an assembly line, 4 modules (equal to the space of 2 lines) are needed to get a logical output from the given space. Space is definitely a big cost, and the above results show that it is better to have an assembly line over modules.
5. Operator’s mentality – This is one of the most crucial factors which decide the future performance of any manufacturing system but most of the time we skip this point taking as a secondary priority.
This is a well known fact that operator’s training and making them multi-skilled takes a good amount of time, resources in terms of money and manpower as well as managements patience also.
Now let’s think about this concept of multi-skilling from operator’s mind set, he may think below two points:
a. Why he should learn different operations or different works when salary is going to be more or less same. Multi-skilling will put extra burden on him without giving any significant monetary benefits.
b. He will learns more than one or two operations and will become a multi-skilled operator, but as soon as he learns all this, he will leave this job and join another company who can pay him better.
In both the cases, the management who invested so much time and money on the operator training and multi-skilling is the loser. These scenes don’t occur to such a scale while working with assembly line.
From above discussed points, it’s clear that such a strategic decision like converting a set-up from assembly line to modular system or vice versa may decide the future of the plant and a good deep thought or brain storming considering all the aspects should be done before decision making.
No doubt, there is nothing left all across the globe for modular systems to prove further. Their success stories reveal the uniqueness and excellence right from automobile sector to apparels.
Modular philosophy has its own advantages and benefits, but the requirement is to run modules with discipline and religiously. There must be no compromise with fundamentals; otherwise blind follow-up of modules may throw bigger challenges.