Flexible manufacturing systems: modular manufacturing

For mass-manufactured products, the bottom line is cost containment. This is affected by:

• how much time is required to prepare the product for manufacturing
• how much time the product is in process (WIP) of being manufactured

Reduction in one or both of these measures will result in a lower manufacturing cost. Flexible manufacturing sewing and construction systems provide for greater flexibility to changes necessary to reduce the time necessary to manufacture fashion products. This flexibility is achieved through cross-training sewing operators, machine flexibility, and/or routing flexibility.

Flexible manufacturing involves one or all of the following activities:

• reorganizing existing equipment on the floor into a new systems approach
• reorganizing the way garments are routed through production
• reorganizing workers into teams that are cross-trained to handle a variety of operations using an assortment of equipment.

In the manufacturing of fashion products, flexible manufacturing systems typically incorporate self-directed work teams or flexible work groups. With all of these, manufacturing management makes a shift away from high individual productivity and low cost to short manufacturing cycles, a small quantity of WIP, and quick delivery of the finished product. Flexible manufacturing is well suited to smaller production runs as compared to the large production runs of the progressive bundle system. The strategy emphasizes group effort, employee involvement, and employee empowerment.

Three types of flexible manufacturing systems are discussed:

• modular manufacturing
• unit production systems
• agile manufacturing.

Modular manufacturing

Modular manufacturing, often referred to as a pull system, is a type of flexible manufacturing where the sewing facility is organized into teams of seven to ten operators each. Operators are cross-trained in all areas of garment construction. Each operator might work on two or three machines. Operators might perform several tasks at each machine, or one machine could be used for a series of assembly operations. Every team is responsible for producing entire garments, instead of one operator being assigned a single operation, such as setting in a sleeve or a zipper (as in the progressive bundle system). Equipment is arranged in modules so that work can be passed from one team member to another, who may work either while standing or sitting. The number of units in each operation may vary from only one to as many as ten.

With modular manufacturing, sewing operators in this factory in Nicaragua work as a team.

Within a module, operators work as a team and solve problems, thus creating a more productive environment. Flaws in production are handled as a team; if a mistake is found, the entire garment is returned to the team, where the operators decide how best to fix it. Therefore, the traditional piece-rate wage is not applicable. The team is paid not only according to the quantity it produces but also by the quality of its work. Pay is based on a collective effort. In theory, if an apparel factory were completely modular, it would be redesigned into modular units, each one capable of producing complete garments in a few hours.

Another advantage of modular manufacturing is that production facilities can shift quickly from manufacturing one type of product category to another. For example, a manufacturer can change its production facilities to accommodate producing intimate apparel, backpacks, and swimwear.

Before deciding to change to a modular manufacturing system, a company must consider these factors:

• Downtime is particularly critical with modular manufacturing methods. Each minute a machine is down, costs money, for it can slow down the entire team’s work progress. A worker’s absence can also slow down production.
• Converting to a modular manufacturing system requires the involvement of all employees, an investment in education and training, a shift of management responsibilities from a few people to the team as a whole, and support from management.
• The shift to modular manufacturing requires a cultural change within a company. Success in creating effective teams depends on knowing how employees think and perform.

Some manufacturing facilities shifted to modular manufacturing in hopes of reducing manufacturing costs. For some companies, however, costs rose at first. New equipment might need to be purchased, cross-training employees costs money, and reduced productivity during training is an additional start-up cost. For companies that commit to modular manufacturing, its cost benefits have been realized by containing costs through inventory reduction, a reduction in WIP, and for some facilities, an improvement in product quality.

Next, let us examine another example of flexible manufacturing systems, unit production systems, and agile manufacturing.