Process Architecture, Lean Manufacturing, and Simulation in Life Sciences
Process architecture
As an integral part of the design of a life science manufacturing facility, process architecture primarily focuses on understanding the client’s manufacturing process and operational requirements; in parallel, process architecture is also deeply involved in the facility layout design, room classifications, finishes used, and, most importantly, GMP compliance. All these design criteria are synonymous and must work harmoniously together.
Understanding a client’s manufacturing process and operational requirements is paramount when designing a facility. This will then help inform the layout of each room and ensure it is appropriately sized for its purpose. This will also help dictate what rooms are required to have direct adjacency to each other. These decisions are often driven by the process equipment used and the client’s manufacturing process. However, despite this design criteria, the underlying goal is to minimize operational costs (smaller footprint and lower classification) and maximize operating efficiency by optimizing room adjacencies.
The classification of a room can drive the operational costs of the facility exponentially. Understanding what level of air quality and process utilities each process operation requires must be vetted with the client and their Quality Assurance department. Once understood, it will help inform mechanical and process utility requirements and thus help right-size the mechanical spaces. For instance, a facility with grade D air will have fewer mechanical demands than if it were grade C. The classification of a room will also drive the level of finishes for the space.
GMP compliance is a design element that must be incorporated into any GMP manufacturing facility’s layout. This compliance informs the facility layout, the flow of materials, and personnel. GMP compliance has a far-reaching impact on the design of a building, so these conversations should occur at the onset of any project and be clearly defined.
Lean manufacturing
Once the facility is designed and built, the operating staff’s goal is to meet their production targets safely and efficiently. One methodology for achieving this, which has been very successful across many industries, not just life sciences, is Lean manufacturing.
Lean manufacturing includes five principles that seek to optimize the manufacturing process:
- Value identification
- Value stream mapping
- Flow
- Pull
- Continuous improvement
Value stream mapping and the transition to flow identifies waste, or non-value-added steps, to eliminate or reduce them. For example, transportation within a facility from one procedure to the next does not add value to the final product. Also, storing material in Work-In-Process staging, typically between equipment or processing steps, does not add value. Staging does serve a purpose, however, to allow upstream or downstream equipment to continue operating for a time in the event of a temporary supply disruption. In effect, it will enable the process to overcome variability so an optimal value exists that balances cost and robustness. A facility incorporating lean principles will minimize travel distances and use only intermediate staging as necessary to overcome variability.
Process modeling and simulation
Process modeling and simulation can be used to compare layouts based on these lean principles. A model that includes travel distances and different transport modes can calculate total travel distances and associated costs for a given layout when the facility is operated at its target throughput. Variability included in the model, using a Monte-Carlo simulation approach, can quantify the WIP levels and, therefore, staging spaces needed to run efficiently even when disturbances are present. Sources of variability may include manual operations, batch failures, equipment failures, and even changes to the production schedule. If variability is found to have a significant impact, the study can justify variability reduction projects.
Process architects strive to develop a cost-effective facility that will be efficiently operated. The ideal is described in Lean manufacturing terms as minimizing non-value-added activities. The approach to “Lean” can be quantified using a model and simulations, including the facility layout and expected process variability.