Operation Management - Process choice and Layout planning
PROCESS CHOICE
Characteristics of project, jobbing, batch, flow, and process production systems, with examples for each.
Project, jobbing, batch, flow and process production are the process types used in manufacturing. The figure below shows the trade off between volume and variety of outputs. In choosing one of these systems, high volume means low variety and high variety means low volume.
(see figure 1)
Project processes - The essence of project processes is that they are all different, so very low volume and very high variety. The identification of activities and their relationship are uncertain, they can change during the production process itself. Each job has a defined start and finish and the time interval between starting two different jobs is quite long. The resources must be organised exclusively for each project and they are re-allocated after the end of them. Examples of this system are movie production companies: obviously every single movie is different from the others.
Jobbing processes - As for project processes, they deal with high variety and low volume. The difference is that the resources are not organised especially for each project, each product has to share them with many others. Although all the products require the same attention, each will differ in its exact needs. Jobbing requires a general purpose layout and highly skilled and versatile workers to interpret drawings and specifications. An example is a painter, who sells his own skill.
Batch processes - With higher volume and lower variety than jobbing process, the essence of these processes is that each time they produce a product, they produce more than one. The size of the batch can be very small (e.g. two or three), therefore batch process becomes very similar to the jobbing, but usually the batches are large, with repetitive operations. They require careful planning and control to ensure proper use and buffer stocks to "decouple" processes. Finally they typically implies high
Characteristics of project, jobbing, batch, flow, and process production systems, with examples for each.
Project, jobbing, batch, flow and process production are the process types used in manufacturing. The figure below shows the trade off between volume and variety of outputs. In choosing one of these systems, high volume means low variety and high variety means low volume.
(see figure 1)
Project processes - The essence of project processes is that they are all different, so very low volume and very high variety. The identification of activities and their relationship are uncertain, they can change during the production process itself. Each job has a defined start and finish and the time interval between starting two different jobs is quite long. The resources must be organised exclusively for each project and they are re-allocated after the end of them. Examples of this system are movie production companies: obviously every single movie is different from the others.
Jobbing processes - As for project processes, they deal with high variety and low volume. The difference is that the resources are not organised especially for each project, each product has to share them with many others. Although all the products require the same attention, each will differ in its exact needs. Jobbing requires a general purpose layout and highly skilled and versatile workers to interpret drawings and specifications. An example is a painter, who sells his own skill.
Batch processes - With higher volume and lower variety than jobbing process, the essence of these processes is that each time they produce a product, they produce more than one. The size of the batch can be very small (e.g. two or three), therefore batch process becomes very similar to the jobbing, but usually the batches are large, with repetitive operations. They require careful planning and control to ensure proper use and buffer stocks to "decouple" processes. Finally they typically implies high