Before an equipment qualification protocol is drafted, here’s a question worth asking: Does every piece of equipment have to go through a qualification lifecycle requiring the same resources, time, and effort, or would commissioning suffice for some?
Some never pause to question whether full commissioning and qualification are truly necessary. Instead, the default option of qualifying every asset is exercised because it appears comprehensive on paper. But is this approach the most efficient use of time and resources, or could a more targeted strategy deliver faster, equally reliable outcomes?
Equipment classification provides a structured way to answer that question. As outlined in the ISPE Baseline Guide Volume 5, the System Classification framework classifies equipment as Direct Impact or Not Direct Impact, providing the basis for determining the qualification strategy.
System Classification According to ISPE
Classification comes down to answering eight questions — a YES to any one of them makes the equipment Direct Impact. All eight have to come back NO before it can be Not Direct Impact. (ISPE Baseline® Guide Volume 5, Section 3.3)
- Does it control a CPP, or otherwise serve a defined CQA?
- Does it have direct contact with the product or process stream?
- Does it produce an excipient, ingredient, or solvent—Water for Injection being the obvious one?
- Is it used for cleaning, sanitising, or sterilising?
- Does it maintain an environment—temperature, humidity, an aseptic zone — that’s a CPP for the process?
- Does it generate or hold data used to accept or reject the batch, or fall under 21 CFR Part 11 or EU GMP Annex 11?
- Does it provide the container closure or product protection?
- Does it apply or check product identification with no independent verification elsewhere?
Classification Outcomes
Every piece of equipment gets sorted into one of two categories based on how it answers those eight questions — Direct Impact or Not Direct Impact.
| Direct Impact (DI) | Not Direct Impact (NDI) |
| Qualified and commissioned | Commissioned only |
| Scope set by CQA/CPP risk to the product | Scope set by SME judgment and HSE criticality |
| System Risk Assessment identifies the CDEs | SME review sets the commissioning scope |
| Full C&Q documentation package | Commissioning documentation only |
Consider the following examples:
- A vial filling machine answers YES at Q2 alone—it’s in direct contact with the product during filling, and a failure there is a direct line to product quality. One YES is enough. It’s Direct Impact and goes through the commissioning and qualification workflow.
- A shrink-wrapping machine sits downstream; it bundles product that’s already capped, stoppered, or sealed. It doesn’t touch product, so Q2 is a clean NO. The question worth pausing on is Q7—product protection. Shrink film does protect the product in transit, so a quick read might call this a YES. But Q7 asks whether this equipment provides the seal on which product quality depends, and the upstream capping or stoppering step already provides that seal. The shrink wrap is a secondary bundle, not the barrier the product relies on. Q7 comes back NO, and so does the rest. The shrink-wrapper is Not Direct Impact. It still goes through commissioning—it just doesn’t go through qualification.
Where classification gets genuinely tricky
Most equipment can be classified with relative ease. Utilities, however, often require a closer evaluation because their classification depends on how they support the process.
- Utilities controlling critical process parameters: Product contact alone does not determine classification. Utilities that control Critical Process Parameters (CPPs) may still be classified as Direct Impact.
Example: A chilled water system cooling a jacketed reactor may never contact the product, but if it controls the reaction temperature (a CPP), it is classified as Direct Impact.
- Utilities with multiple points of use: The same utility can serve both Direct Impact and Not Direct Impact applications. Classification should be based on the specific point of use rather than the utility itself.
Example: Compressed air used to dry product-contact equipment after cleaning may be classified as Direct Impact. The same compressed air used only to operate non-product-contact equipment is Not Direct Impact.
- Function over equipment type: Classify systems such as nitrogen, vacuum, or compressed air according to their function in the process, not their names.
Example: Nitrogen used for product blanketing is Direct Impact, whereas nitrogen used only for line pressurisation may not be.
The Bottom Line
The most effective qualification programmes do not qualify every equipment. They are selective. Equipment classification provides the framework for making that decision consistently, ensuring that the qualification effort, project resources, and regulatory focus remain aligned with actual product and process risk.
Reference
1. ISPE Baseline® Guide: Commissioning and Qualification, Volume 5, Second Edition. International Society for Pharmaceutical Engineering (ISPE), 2019. ISBN 978-1-946964-23-6.