Surmounting the Challenges of Process Scale-Up

Scaling up a process for increased demand is an exciting and challenging time for any business. There is a tendency for teams to simplify or expedite the process, and making this mistake incorporates risk. This article explores a central process for creating and maintaining a basis for improving scale-up success. I wish to thank my coauthor, Dan Voit, CEO of Blentech Corp., for contributing to this column.

The term “scale-up” is universally used to describe production increases, but more than this, scaling up is a long, complex activity requiring advanced risk management and highly disciplined, creative problem solving in cross-functional and even multi-company teams. Whether your team is a) increasing production to accommodate surging demand; b) launching a new product previously on the benchtop; or c) passing through a threshold of capacity with a “step change” in production, you are scaling up, and each case is unique.

• Surging Demand. In this category of scale-up, many teams start their journey by identifying what they consider to be the limiting operation in their process and shop the market for a similar but larger machine to increase production rate. This may mean if they cook a product in a 200-gallon kettle they simply seek to purchase a larger version of the same technology. These teams often apply the “10x rule” with the thought that if increases in capacity are equal to or less than 10 times, then risks are managed. While not technically a problem, this practice carries an often-unquantified risk. It limits the possibility of incorporating new technology. With the pace that new equipment, processes, and automation are being developed, businesses need to stay on the leading edge of innovation in all these areas. Rules of thumb provide false security. 

• Benchtop. When scaling from the benchtop, process definition is vital. Steps used on the benchtop often must be changed to reach larger scale. An example is a process like Maillard browning. This reaction is easily achieved in products arranged on a cook surface with a large surface area to volume ratio (SA/V). Yet, as equipment capacity is increased, ratios change, and this affects process. Specifically, reduced SA/V may eliminate the potential to “brown” effectively. Defining the key changes in food composition, structure, and/or the reactions required helps anticipate these issues. Asking questions like “how will the increase in product depth or reduced surface temperature impact browning?” is critical to successful scale-up.

• Step Change. A step change in existing processes involves a targeted risk management approach. Existing products have existing customers, and existing customers prefer the product to remain the same. Step changes often occur by substituting processes within an existing facility with a higher output, new technology, or added automation. A well-defined understanding of the critical parameters from all perspectives for producing the target product is clear.

Each case is unique, but the good news is that there are universally applicable approaches that can be applied to each case. Additionally, there are common concerns and pitfalls, and this article will explore several of them.

Mapping a Process
Regardless of the category of scale-up, the starting point is the same: Define the current process and define the future need. In practice, the best place to begin is breaking down the process into unit operations. This begins simply by creating a block flow diagram. This creation is iterative and collaborative. The diagram is the beachhead for the creative iteration required to define a process and create consensus. To accomplish this, teams effectively communicate complex ideas and apply systems thinking. An excellent resource to understanding systems thinking is the Ted Talk by Tom Wujec “Got a Wicked Problem?”

Beginning is as simple as walking through the steps, defining each key unit operation as a node, and connecting with links. The document grows in complexity and value as the underlying processes, physical, chemical, and structural affecting product and profitability are defined. As the map comes into focus, the team incorporates the input from the internal or consultative specialists who add the critical detail needed to provide the basis for scale-up. Internal team members like sanitation specialists and quality assurance team members are key at this point. Often, applications specialists from equipment and ingredient suppliers add layers of perspective that add value.

Define Your Strategy
Second, but no less critical, a clearly defined company strategy, short term and long term provides the target for scale-up. A clear definition of strategy allows the team to consider the future effect in reference to the basis block flow. There are often diverse technologies that can be employed for each unit operation, each yielding different advantages and considerations. Within this strategy should be a clear target for throughput and growth needs, including production needs, packing size and type, and potential future products.

Identify Concerns
The block flow is also used to define the new or future state of the line. By comparing the detailed existing process with a detailed future process, concerns can be pinpointed and addressed. There are common categories of considerations to explore while iterating a scale-up concept. Experience has shown us that gathering the specialists or experts on your team will allow you to compare the concepts and identify areas requiring further information to make an informed decision. These areas include the following:

• Formulation. Producing more product often means that suppliers need to be considered or reformulation is needed to incorporate a more robust ingredient. An example is using tomato paste in place of a tomato puree to save on cost and improve operational efficiency.

• Process. A big decision is “batch or continuous.” Often continuous processes offer more efficiency over time while batch processes offer flexibility. In both cases, the block flow is a basis, and at this point, it’s now possible to calculate process timing and evaluate material handling strategies. Using the future production needs, the effects of factors such as SA/V can be used to recalculate processes such as heating, cooling, and mixing times. This is then reviewed by the quality and development teams. At Blentech Corp., Santa Rosa, Calif., a Production Time Resource Schedule (PTRS) tool is used to create a visualization of the time and energy effects of scale-up on a process.

• Equipment. After processes are defined, the specific equipment designs are considered for short- and long-term needs, balancing the strategic goals. Key points are automation, data collection, training, operator capabilities, staffing, maintenance costs, and the durability of the design. Simple questions like “will this equipment allow us to produce what we need in two or even 10 years?” need to be answered.

Bringing It Together
With multifactor, multidisciplinary issues at play, collaborative tools like Google Docs greatly streamline the ability to aggregate information across teams. As the decisions affecting formulation, process, and equipment are finalized, several specific areas should be considered.

Under the heading of product quality, considerations include the following: sampling and quality assurance needs; effects on ingredient source and type; formulation adjustments; and effects on kinetic processes (browning or enzymatic reactions), mass transfer, heat transfer and mixing operations (cooking and cooling), and emulsifications.

The considerations in terms of efficiency/profitability are as follows: material handling and ingredient loading; effects on yield; rework strategies; and strategy to manage work in process or staging.

As for safety/compliance, the issues include regulatory compliance, sanitation and food safety, process validation/food safety, process control and monitoring, and personnel safety.

Each of the preceding topics is an example of where functional experts can be incorporated to develop understanding. An example is defining the effect of mixing, such as shear effects on product characteristics. Common problems with mixing scale-up include particulate damage, particulate separation, inadequate dispersion, poor emulsion formation, and air incorporation. These influence product quality and therefore benefit from experiential guidance.

Automation can offer good returns on investment, but it can limit flexibility if used incorrectly. As such, a big question is “how much automation to include?” With a block flow diagram in place, teams can determine which processes, tasks, or steps are consistent and unchanging and therefore best suited for automation. Specifics for data collection and instrumentation are next designed using a Piping and Instrumentation Diagram (P&ID). Effective automation allows human teams to stay focused on the operations that are more dynamic in nature, while routine data is automatically collected.

Starting Up the New Line
Automated processes generally require more time and training to start up than simple isolated operations. The pharmaceutical industry uses a phased approach to start up: Installation Qualification (IQ), Operational Qualification (OQ), Performance Qualification (PQ), and Process Validation (PV). Although less frequently discussed in the food industry, the model is perfectly suited for a) complex processes, b) large scale-ups, and c) highly automated systems. Learning new information along the journey is common and while it’s comparatively simple to check that a machine is physically installed or that it mechanically operates as expected, the processes of PQ and PV are empirical in nature. Formulation adjustments, process conditions, and sometimes equipment designs need to be changed to accommodate the new learnings during scale-up.

Stepping back from the important details of our food business and seeing the big picture, it’s important to recognize the disruptive effects of technology and automation. To stay relevant, scale-up practices should be adapted to incorporate the technology of tomorrow. Collaboration with a consistent basis adds significant value when surmounting the challenges involved in process scale-up.

Tara McHugh, PhD, Contributing Editor
Research Leader, USDA Agricultural Research Service, Albany, Calif.
[email protected]