Statistical Process Control (SPC), is critical in any manufacturing environment to ensure consistent, quality product is being produced. This SPC graph shows a 24-hour period in which a single, randomly-sampled 1-gram (or 1000 mg) pharmaceutical tablet is weighed from the same batch every hour. Historical data (or possibly regulatory agencies) have set the spec limits at ± 0.005 g.
Our example batch is trending high, but still within specifications. This is common amongst certain pharmaceutical formulations (e.g., metformin). For example, a product may absorb water from the air and can take on weight during production. SPC trending could warn production staff that conditions (humidity, compression, hardness, etc.) need adjusting on the production floor/press before a problem occurs. This simple proactive adjustment could save thousands in prevented production costs (e.g., non-conformance, deviation, recall, quality intervention, etc.).