No. In most regulated manufacturing environments, you do not need to rewrite every procedure before going live. You do, however, need to identify which procedures are impacted by the new system or workflow and update those in a controlled, documented way.
What actually needs to change
At minimum, you should update and reapprove procedures that:
- Reference tools or media you are replacing (for example, paper travelers, spreadsheets, legacy terminals).
- Describe step-by-step execution that will now be performed in a different system or sequence.
- Define roles and responsibilities that are changing (for example, who can release work, approve WIs, disposition NCRs).
- Define records that will now be created, stored, or retrieved differently (for example, electronic travelers, eDHR, digital signatures).
- Are used as evidence in audits or customer reviews and would no longer be factually correct at go-live.
Anything that is materially touched by the new system should be brought into alignment before you move production onto it, or clearly covered by an interim controlled approach (for example, a deviation, bridging procedure, or controlled work instruction addendum).
What can be phased in
In brownfield plants with layered legacy systems, it is usually more practical to phase procedure updates than to attempt a one-time rewrite of everything. Often you can safely defer rewriting procedures that:
- Describe upstream or downstream processes that are not in scope for the initial rollout.
- Address rare or exception scenarios that can be covered by temporary instructions while you stabilize the baseline flow.
- Contain general policy language that is still true regardless of the specific tools in use.
This phased approach must still be under document control: maintain a clear list of procedures to be updated, target dates, owners, and how you will manage interim gaps.
Regulatory and quality constraints
In a regulated environment, auditors and customers will focus less on whether you rewrote everything and more on whether:
- The procedures in force at go-live actually describe how work is performed in the new system.
- There is documented impact assessment for the change (for example, which SOPs, WIs, forms, and training are affected).
- Document control and version governance are intact (superseded versions are controlled, new versions are approved and effective).
- Training records show relevant personnel were trained to the updated procedures before or at the time of use.
- You have traceability from requirements and risk analysis into the digital workflow and associated documentation.
Where applicable, your QMS may require formal change control, validation, and documented user acceptance testing before procedures referencing the new system become effective.
Coexistence with legacy systems
Most plants will run hybrid processes for some period: part of the flow in the new system, part still on legacy tools or paper. Your procedures should reflect this reality clearly. That usually means:
- Explicitly stating when operators use the new tool vs legacy system (for example, by product family, line, or site).
- Defining how records from different systems fit together for traceability and audits.
- Addressing failure modes, such as system downtime, and how to revert to paper or fallback systems in a controlled way.
Attempting a full, simultaneous documentation rewrite across all systems often fails in long-lifecycle, highly regulated environments due to validation burden, high review/approval load, and the risk of inconsistencies creeping in. A staged update with clear impact analysis and traceability is usually more robust.
Practical approach to scope the work
A pragmatic way to decide how much to rewrite before go-live is to:
- Map scope and interfaces: Identify which processes, products, and sites are in scope for the new system and where it interfaces with existing MES/ERP/PLM/QMS tools.
- Perform a document impact assessment: For in-scope areas, list all relevant SOPs, work instructions, forms, and checklists. Flag those that are incorrect or incomplete if the new system is used.
- Prioritize critical-path procedures: Update first those that govern safety-critical, quality-critical, or regulatory-record-related steps, and anything required to release product.
- Define bridging controls: Where you cannot update a procedure before go-live, define a temporary controlled instruction or deviation and train to it.
- Plan post-go-live cleanup: Establish a realistic schedule and ownership to bring remaining procedures into alignment while the system is running.
Key tradeoffs
You are trading between:
- Risk of misalignment: Going live with outdated procedures that do not match the system increases the risk of audit findings, operator confusion, and inconsistent execution.
- Change fatigue and delay: Forcing a big-bang rewrite of everything can overwhelm document control, reviewers, and trainers, delaying benefits and introducing errors.
A risk-based, scoped update of affected procedures, backed by strong document control, traceability, and training, is usually the most defensible path in regulated, mixed-system environments.
