How batch production works
Each process step works on the whole batch before passing it on: a mixer makes 500 kg of one formulation, the filling line runs 2,000 bottles of it, the packer cases them, then the line is cleaned and changed over for the next product. The batch is tracked as a unit, which is why regulated industries such as pharmaceuticals and food rely on it for traceability.
Where it is used
Food and beverage, pharmaceuticals, chemicals, paints, bakeries, printing, textiles and any plant that makes many variants on shared equipment.
Advantages
- Flexibility to make a range of products on one set of equipment.
- Lower equipment cost than a dedicated line per product.
- Traceability: every unit belongs to a numbered batch with its records.
Costs
- Inventory: every batch waits at each stage for the rest of the batch.
- Lead time: a unit's path through the plant is dominated by waiting.
- Changeover downtime between batches.
- Quality risk: a defect found at the end affects the whole batch.
Batch production and lean
Lean does not abolish batches; it shrinks them. SMED reduces changeover time, which makes smaller batches economic; smaller batches cut inventory and lead time and expose defects sooner. The ideal is one-piece flow, reached in some processes and approached in others.
Batch production and daily management
Batch plants run on schedule adherence, changeover time, yield and right-first-time. Those measures sit on the tier board by line; a late batch, a long changeover or a rejected batch is raised at the daily meeting as a problem with an owner, and repeat causes move into problem solving.