Lean has been enthusiastically embraced by our industry because the tools are simple and improvement can be realized quickly.
Although Lean is often initiated because of cost or efficiency reasons, there is another perspective to Lean that is often
overlooked: quality.
Figure 5. DMAIC and Lean tools deployed in the Shewhart Cycle
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Our industry should think of Lean as a quality initiative—not a business-driven one. While it is true that the basis for Lean
is to eliminate waste and maximize the value-added activities of a process, another benefit of Lean is the way it simplifies
and standardizes the process. The result is improved predictability. If you map the DMAIC and Lean tools together against
the Shewhart PDCA Cycle, you find they follow the same framework; the tools within both toolkits are designed to address the
same basic requirements of the PDCA cycle (Figure 5).
VALIDATION AND PLAN, DO, CHECK, ACT
Table 1a. Summary of DMAIC phase deliverables (continued)
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Mapping validation, as applied by the biopharmaceutical industry today, may seem inconsistent with the principles of the Shewhart
PDCA Cycle, DMAIC, and Lean. The basis of traditional validation is verification against predetermined acceptance criteria.
How-ever, if we divide the validation process into its components, there is more similarity than difference between validation
and these improvement methods. The steps of the validation life cycle map well to the Control, Measure, and Analyze phases
of the DMAIC roadmap. What is missing is the Improve stage.
Table 1b. DMAIC phase deliverables
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Six Sigma and Lean principles are predicated on the absolute requirements of demonstrating that the process is in control.
By building on an efficient and objective framework for characterizing, measuring, and optimizing a process, it is possible
to achieve a level of confidence that the process will be predictable and reproducible. No amount of testing will ever approach
this level of confidence; heightened testing and large sampling can still only infer the process is in control. (As many have
said, you cannot test quality into the product.) The irony in applying validation to the PDCA model is that its efficacy is
only as good as one's understanding of the key process input variables that steer the process. In the absence of this, validation
degenerates to a paper exercise.
CONCLUSION
Quick Recap
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The twenty-first century GMP initiative advocates the need for building process understanding throughout the process development
lifecycle. Tools such as Six Sigma, DMAIC, and Lean Manufacturing provide a framework for objective characterization and analysis
of a process's key parameters. This knowledge, coupled with a quality system framework for specification, in-process, and
release testing, can significantly elevate the level of quality built into the final product or process. While at first glance
validation might appear to be inconsistent with these improvement initiatives, the elements of the validation lifecycle map
to the control, measure, and analysis phases of the PDCA lifecycle. The most effective application of validation is achieved
by using these optimization tools in the process characterization and development phases of a process long before validation.
Until characterization and evaluation frameworks are more fully integrated into the drug development lifecycle, validation
will remain a costly and time-consuming exercise capable only of providing limited assurance of process and product stability.
Bikash Chatterjee is the chief operating officer of Pharmatech Associates, 1098 Foster City Blvd., Foster City, CA 94404;
tel 650.227.0177 fax 650-227-0176;
bchatterjee@pharmatechassociates.com
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