People often wonder “When is the best time to incorporate simulation into a project?” The answer, without a doubt, is at the earliest possible moment — when an idea for a significant system change or major investment is first being discussed. While it is true that at this early point in a project there are many unknowns and often very little data, simulation can still provide significant value with often a very low level of effort. While the specific issues obviously vary based on the exact systems, at these early stages you are often looking for gross measures of capacity planning and throughput analysis, impact on other facilities, and early identification of potential problem areas.
With modern tools, you can often create high-level simulation models to study such issues in not much more time than it might take to develop a comparable spreadsheet. But instead of using a spreadsheet that is limited to often misleading static analysis and fairly simple relationships, simulation can take full account of the variation and complexity present in most real systems. And as the project concepts mature, the simulation can expand and mature along with it and continually provide value at each step of the project.
For example a project might go through phases with typical questions like these:
1. Early concept validation – How will this new system work? What is the estimated capacity and throughput? What impact will this have on existing facilities? How can I communicate potential issues to stakeholders?
2. High-level system design – What components should be included? What are realistic design objectives? Evaluation of trade-offs of various investments and level of capability provided. High-level bottleneck analysis. Identify “surprises” while they are still easy to deal with.
3. Detailed system design – What specific equipment should be used (e.g., degree and type of automation)? What procedures should be implemented? What reliability can be expected and how will that impact performance and costs?
4. Implementation –Does the system perform as expected and if not, why not and how can it be “fixed”? What is the optimal staffing? When is a “change order” worthwhile?
5. Start-up – What is the impact of learning curves? What are realistic expectations during transition to full capacity? How long will that transition require? What special procedures should be put in place during that transition, what is their cost, and how soon can they be phased out?
6. Operation – How to plan and schedule the intermediate and short-term facility operation? How to effectively deal with the variability present in all systems (e.g., equipment and personnel problems, demand variation, shifting priorities, …)? How well is the system performing on the actual demand as opposed to the originally anticipated or “optimal” demand?
7. System improvement/re-design – As the system reaches stable operation, new ideas, procedures, and technologies will occur. What would be the impact of incorporating changes? Which changes have the best ROI? How do the changes relate to each other?
Until next time … Happy Modeling!