1.3 COMPUTER CONTROLLED BATCH PROCESSES

 

• The nature of Batch processes,

- Batch processes deal with discrete quantities of raw materials or products.

- batch processes allow the tracking of these discrete quantities of materials or products

- batch processes allow more than one type of product to be processed simultaneously, as long as the products are separated by the equipment layout.

- Batch processes entail movement of discrete product from processing area to processing area

- Batch processes have recipes (or processing instructions) associated with each load of raw material to be processed into product.

- Batch processes have more complex logic associated with processing than is found in continuous processes

- Batch processes often include normal steps that can fail, and thus also include special steps to be taken in the event of a failure.

 

• The nature of steps in a batch process,

- Each step can be simple or complex in nature, consisting of one or more operations

- Generally, once a step is started it must be completed to be successful.

- It is not uncommon to require some operator approval before leaving one step and starting the next.

- There is frequently provision for non-normal exits to be taken because of operator intervention, equipment failure or the detection of hazardous conditions.

- Depending on the recipe for the product being processed, a step may be bypassed for some products.

- The processing operations for each step are generally under recipe control, but may be modified by operator override action.

• A typical process step