Understanding Process Manufacturing Planning

Process manufacturing results in products such as liquids, fibers, powders, and gases. Pharmaceuticals, foodstuffs, and beverages are typical examples of process products. Products such as these are usually manufactured by a two-step process:

1. Mixing or blending

2. Filling or packaging

These kinds of products might involve intermediate steps, such as curing, baking, or preparation.

Process manufacturing uses ingredients and bills of material. Ingredients can be either consumed or produced during the manufacturing process. In a process bill of material, the quantity of a component can vary, according to its grade or potency.

Unique features of process manufacturing are:

• Pacing co-products.

• Planned co-products (by-products are unplanned).

• Additional processing options in MPS/MRP.

Process manufacturing produces co-products and by-products. A co-product is a saleable end item that results from a process. A by-product is a material of value that is produced incidental to or as a residual of the process.

The different types of process manufacturing are:

• Batch

• Continuous

In batch processing, you usually produce a product in a standard run or lot size that is determined by vessel size, line rates, or standard run length. Because of the life cycle of the product after its completion, you typically schedule items that are made this way in short production runs. Co-products and by-products can be generated during batch processing. Typical items that are produced with batch processing include:

• Pharmaceuticals

• Foods

• Inks and paints

• Glues

• Oil or chemical products

In the continuous flow environment, production runs typically continue for an extended duration. Equipment is dedicated to one product or product line. This method of manufacturing is characterized by difficulty in matching output volume with demand and varying yield from process operations. Examples are petroleum-based products and water purification. Co-products and by-products are generally more prevalent in continuous processing than in batch processing.

Master Production Scheduling (MPS) calculates the time series for co-products. Demand for the co-product generates MPS order messages to drive the production process. Co-products that are fully satisfied by the process do not receive order messages. Processes might also make a by-product that has value but is not the central purpose of the process. For example, the lubricant process has co-products of household lubricant and graphite lubricant, and a by-product of sludge. The lubricant would not be processed primarily to obtain sludge.

Usually, both batch and continuous processing methods require extensive record keeping, such as recording quality and tolerance values during the process, and strict adherence to lot tracing and tracking.