• FMEA Vs. System Risk Structures (SRS): Which Is More Useful?

    In this article, Mark Witcher, Ph.D., discusses the many failure modes of FMEA and risk priority number (RPN), comparing and contrasting it with system risk structures (SRS) and adjusted risk likelihood (RPN). He concludes that one of these is more useful than the other for pharma and medical devices; which one is it?

  • Using System Risk Structures To Understand And Balance Risk/Benefit Trade-offs

    The ICH 31000 guidance defines a risk as the “impact of uncertainty on objectives.” As a follow-up to his article on why we should replace the RPN with the adjusted risk likelihood (ARL), Mark Witcher describes how system risk structures can be used to simultaneously understand and manage both risks and benefits. 

  • Rating Risk Events: Why Adjusted Risk Likelihood (ARL) Should Replace Risk Priority Number (RPN)

    While the RPN primarily represents a risk event’s severity, perhaps a more important attribute to focus on is the risk event’s likelihood of occurrence. In this provocative article, Mark Witcher, Ph.D., proposes an adjusted risk likelihood rating approach that emphasizes a risk event’s likelihood of occurrence.

  • Revising Annex 1: A Case Study In Controlling Operating Risks By Understanding Uncertainty

    Unfortunately, the pharmaceutical industry does not understand how to control a risk’s likelihood of occurrence. The current draft of EU GMP Annex 1 is an example of the industry’s focus on a risk’s severity while not understanding or evaluating a risk’s uncertainty and thus defaulting to using the precautionary principle for guidance.

  • Can We Eradicate Tech Transfer?

    While warp-speed manufacturing is a pandemic term, the concept is important to the FDA’s 21st century vision of “a maximally efficient, agile, flexible pharmaceutical manufacturing sector that reliably produces high-quality drugs without extensive oversight.” Reaching 21st century performance requires replacing many 20th century practices.

  • A Functional History Of Process Validation: Part 2 – The Key To A More Effective Future

    Part 1 of this two-part series discussed the history and underlying concepts of process validation (PV), which is required for dealing with the increasingly sophisticated pharmaceutical manufacturing processes necessary for realizing advanced medical therapies. This article describes how PV concepts can be evolved so the industry can better develop, manufacture, and launch the next generations of biopharmaceutical products.

  • A Functional History Of Process Validation, Part 1 – A Weak Foundation

    This article is the first of a two-part series that describes the origins of process validation to explain the underlying concepts necessary to control the advanced bioprocess manufacturing technologies required to make the next generations of biopharmaceutical therapies.

  • System Risk Structures: A New Framework For Avoiding Disaster

    Risks are ubiquitous, occurring in every aspect of our personal and professional lives. This article describes how pharmaceutical development and manufacturing risks can be easily understood and effectively managed using straightforward concepts.

  • What Managing Personal SARS-CoV-2 Risks Can Teach Us About Managing Pharma Risks

    This article describes how the basic principles of managing personal risks of being infected by a respiratory virus can be used to manage risks for developing and manufacturing pharmaceuticals. The goal is to elucidate the basic principles of understanding, managing, and communicating a wide variety of risks from the trivially simple to the very complex.

  • 2 (Major) Impediments To Faster Biopharma Product Development

    As pharma products have become more complicated, companies have become bogged down in accomplishing their mission of launching new products because of complex regulatory requirements, convoluted management approaches, and inefficient resources and methods that add time and cost to moving new products from research to patients.


Mark F. Witcher

Mark F. Witcher, Ph.D., has over 35 years of experience in biopharmaceuticals. He currently consults with a few select companies. Previously, he worked for several engineering companies on feasibility and conceptual design studies for advanced biopharmaceutical manufacturing facilities. Witcher was an independent consultant in the biopharmaceutical industry for 15 years on operational issues related to: product and process development, strategic business development, clinical and commercial manufacturing, tech transfer, and facility design. He also taught courses on process validation for ISPE. He was previously the SVP of manufacturing operations for Covance Biotechnology Services, where he was responsible for the design, construction, start-up, and operation of their $50-million contract manufacturing facility. Prior to joining Covance, Witcher was VP of manufacturing at Amgen. You can reach him at or on LinkedIn (