Sit or Stand? Reflections on the Introduction of Modular Work Organization in the Clothing Industry
Over the last few years, the clothing industry has undergone numerous changes, leading companies to introduce a range of innovations. One of these is "modular team sewing", of which the "stand-up" variant is the most advanced form. Research by Dunlop and Weil shows that very few companies have succeeded in introducing this change and, in order to do so, they have had to follow a three-step process. Why is the introduction of this advanced form of work organization not more widespread? We believe that because the differences between traditional and modular work organization are so great it is very difficult for sewing machine operators working in the "traditional system" to move directly to the new approach. Consequently, we propose the introduction of an intermediate step in the process, namely the "sit-down" variant, in order to prepare operators for the "stand-up" variant.
The traditional approach in the clothing industry is the progressive bundle system (PBS) based on the accumulation of in-process inventories, a system in which work is highly fragmented and deskilled. Each operation is done by a single worker operating a stationary sewing machine. Each worker receives a bundle of unfinished garments and then performs a single operation on each garment in the bundle. The completed bundle is then placed in a buffer with other bundles that have been completed to that point, and the bundles in the buffer are then ready for the next operator in the sequence. PBS focuses on direct labour content reduction. First, the system depends on buffers between assembly operations to minimize workers downtime given varying assembly time requirements for different operations. Second, the system must create sufficient buffers between assembly steps in order to keep everyone in the sewing room occupied. PBS is a «push» system in which bundles of work are moved from station to station and is well suited to piecework compensation because operators are normally provided large quantities of work to do in a given time, allowing the development of high individual efficiencies. Modular production entails grouping assembly tasks and assigning that task to members of the module rather than fragmenting assembly into a long series of small steps. The work team works together to produce a major portion of the final garment or, in some cases, the entire garment. In the stand-up module, the two most flexible approaches are the «hand off» system (in which each operator completes a task and passes that garment on to the next person) and «bump back» (in which an operator is replaced at any point in the cycle with the next operator, who has just finished a cycle). Each person moves to a previous operation within a specified range of operations. In this manner a single garment never stops moving and throughput times virtually equal to the actual value of labour content can be achieved. Empowering the production worker with the authority to make some or all of the decisions involving the performance of a task is the basic principle which sets the module concept apart from the progressive bundle system. Team members can decide on when to move for balancing, and when cross-training is needed. Other areas of authority may include workstation design, operation method, machine configuration and, in rare cases, work group schedules.
Balancing in PBS is almost exclusively a static exercise that determines the closest round number of machines and people required per operation to produce a given demand for the product. This is an exclusively managerial activity. The goal is simply to keep every person and every machine busy, and this is achieved by maintaining a high level of work-in-process inventory. By contrast, in the hand-off modular approach, the only work-in-process is in the hand of the operators. This «pull» system uses a team of multiskilled workers who stand and walk between different machines and tasks. Each sewing specialist is assigned to a zone of sequential tasks. She performs her set of tasks and then hands her garment to the next person in the module. A defined pattern of movement is repeated throughout the day. When the last specialist completes a garment, she goes back to the previous one and takes over her work. This person then goes back to the specialist prior to her, and so on, until the rotation ends at the first person in the module. There are no balancing decisions to be made. By design, hand-off modules are self-balancing. On the other hand, in the bump-back approach, balancing decisions have to be made by operators.
Sit-down modules have the following characteristics. Operators are seated in their workstation. There is some amount of cross-training and at least some operators are capable of moving between tasks (not necessarily sequentially). Work-in-process is established for each operation and for the entire production line as a control mechanism. Supervisors and engineers can no longer focus on workers in isolation but must consider the effect of the action of each worker and the design of each task on the functioning of the group. Workers must become involved in the pace of production of their co-workers. Operators must help other team members who fall behind. Any imbalances in the production process will be corrected without any intervention by the supervisor. This requires some of the operators to be able to do a variety of tasks. The sit-down module is anhybrid work system having similarities with both PBS and stand-up module. The sit-down module has its own requirements as a production system, but we believe that as a cultural system it can be used as a transition toward stand-up modules by preparing operators to ease into group functioning. This transition is sometime necessary to allow operators to move from the highly individualistic PBS system to the group-oriented stand-up module.