Better Factory Designs with Manufacturing Simulation

Engineering drawing ready to be converted to a manufacturing simualtion

Manufacturing Simulation

Manufacturing simulation lets you create models of your production processes and supporting systems. It is not just equipment and cycle times, you can include labour, skills, tools, product mixes, shift patterns and complex routing. As long as you can describe your processes and decision making you can create a useful model.

 

At what stage should you create a Manufacturing Simulation?

You can model a manufacturing process at any stage. You can model a concept, a design, or an existing production line. At each stage there will be a different level of granularity. This is fine because you will be asking the simulation very different questions. For example, at the concept stage you will be concerned about how things fit together and how big they need to be to meet the design brief. With a model of an existing facility, you will have a high level of details such as cycle times and resource scheduling. This is important as you will be asking detailed questions such as how long it will take to make a sales order with a certain product mix.

If you are interested in creating a simulation, take a look at our ‘Factory Simulation: It’s all in the preparation’ article. This article describes how to get a good project scope and starting question for your model.

 

Simulation at concept stage

At the concept stage you will have limited information, just an idea of how you want the manufacturing facility to work, and what and how much you want to produce. At this stage you may just want to compare different concepts. This will allow you to shortlist the best and take a more detailed look at them. When you have used simulation to identify the right concept, you can add more details and take a deeper look at balance of plant and approximate performance.

It is a good idea at this stage to share the model with your colleagues, and visually show them your ideas. This allows you to gain useful insight about the process and get early buy-in from key stakeholders. As you are only in the concept phase it is quick and inexpensive to make major changes to the design. With a simulation you can respond to feedback quickly, if the changes are simple, you can even make them in the same meeting. This ability to respond quickly, and test recommendations, means you can rule out dead ends and implement good suggestions quickly. This all results in a better design concept and a better outcome.

Simulation at engineering design stage

Once you have an agreed concept you can start producing the detailed designs. This information can be fed into the model as it is generated. This will give you a feel for how the current design will perform. The model will also highlight where there are gaps in information, and importantly how sensitive those gaps are to the model’s outcomes. Identifying these key pieces of information allows you to develop a technical scale-up plan, using the model you can identify all the key information needed for the detailed engineering. This plan will define the required equipment trials, pilot production runs, and more detail discussions with equipment suppliers.

A more detailed simulation will allow you to build accurate labour requirements and dynamic material usages. This can be used to generate accurate operational expenditure (OpEx), resource requirements, and raw materials requirements. This is great as it allows involvement by Finance, Operations, Procurement and Warehousing at a much earlier stage. Early enough that they can suggest changes to the design before it has been finalised.

When the detail design has been completed it can be presented to the stakeholders along with the simulation of the design. This will provide a visual representation of the design that can be interrogated by everybody. This will allow the design to be validated against the design scope and allows the stakeholders to challenge different aspects of the design. Minor changes here can easily be tested and implemented before any concrete has been poured. Again, this results in a better design with better outcomes.

Design development

This is a good point to develop the design further. An accurate simulation allows you to assess a lot of things that would normally only occur after the facility has been built. And of course, it is much easier to make these changes whilst the design is still on paper. Figure 1 shows the classic cost of change versus the ability to make change as a project progresses.

Areas of the design that you can develop are:

  1. You can work on reducing capital costs by identifying any underutilised or oversized equipment. Using the model, you can simulate potential plant cost savings and quickly quantify the impact of any change to equipment specifications.
  2. You can identify improvement opportunities by identifying any bottlenecks, wasted resources, or high stock levels. This gives you an opportunity to compress delivery times, reduce operational costs and increase throughputs.
  3. You can conduct a cost-benefit analysis on all those optional extras and nice to haves. There may be some real value in adding capabilities at the design stage, instead of ad-hoc changes to an existing plant.

 

Figure 1. Cost of change versus the ability to make change (www.praxisframework.org).

Simulation of an existing manufacturing facility

A model of your existing manufacturing facility gives you the opportunity to solve operational problems. It can be used to investigate performance issues and identify their source. You can replicate rare events and identify their causes. Once you have identified the source of an issue you can virtually test ways to fix them. This means you can confidently implement a working solution to your problem.

If you are planning on removing a bottleneck through investment, you can first test the scenario in your model. Quite often an improvement just moves a bottleneck elsewhere in your facility and you don’t achieve the full benefit of your investment. Using your model, you can assess a number of different investment plans, and determine the most efficient use of capital.

One of the fun features of simulation is the ability to create scripted events. We often use them to simulate serious equipment breakdowns. For example, what happens to production if a conveyor fails. This scenario allows you to assess built in equipment redundancies, inventory levels and throughput recovery. Importantly you can work out how quickly a repair needs to take before it impacts on production.

Take a look at our video example of using scripted events to determine manufacturing resilience.

https://www.youtube.com/watch?v=bvKIBCxQW0Q

A screen shot of a manufacturing simulation. This is demonstrating a specific product mix running through a production facility.

Figure 2. Using simulation and scripted events to determine plant resilience.

Simulation of product mix

Over time markets change. What was once a successful product starts to become less desirable. At this point you may start looking at introducing new products to your production facility. This typically results in changes to production routes, cycle times and possibly new equipment. With your model you can simulate different product mixes moving through your production facilities. The model will help you determine the economics and throughputs for the new product mix. And ultimately help you decide if it is worth upgrading your old production facilities.

Take a look at our video example of using simulation to determine the throughput of different product mixes.

https://www.youtube.com/watch?v=JulgTaKRmhE

Screen shot of a simulation of a fertiliser plant. The model has simulated a breakdown of a key material conveyor.

Figure 3. Using simulation to determine the economics and throughputs of different product mixes.

Summary of some of the benefits of manufacturing simulation

Here are the key benefits described in this article:

  1. Share the model with your colleagues. The animated representation of your design makes it easy to communicate your plans to stakeholders. Earning valuable buy-in and useful feedback.
  2. Develop a technical scale-up plan. Creating a model highlights the key information requirement for the detailed design. This can be used to plan equipment trials, pilot production and supplier conversations.
  3. Reducing capital costs. Using the model during the design phase, you can identify under-utilised and over-sized equipment, allowing you to confidently reduce the capital costs.
  4. Identify improvement opportunities. A simulation of a detailed manufacturing facility design, allows your team to identify bottlenecks, wasted resources and high stock levels. This can then be resolved at the design stage, not after the facility has been built.
  5. Cost-benefit analysis. The benefits of optional extras can be quantified, and real value can be identified early, instead of ad-hoc changes later.
  6. Solve operational problems. The dynamic nature of the model allows the genesis of problems to be observed. Working solutions can then be identified and tested.
  7. Determine the most efficient use of capital. Different investment scenarios can be tested with key stakeholders, and the best one identified and implemented.
  8. Determine manufacturing resilience. Using scripted events, you can test the resilience of the production facility against breakdowns of key equipment.
  9. Economics and throughputs for the new product mix. Sales plans can be tested virtually through the production facility, making sure you can meet delivery dates and make money.

 

Getting started

If you are new to simulation, you can find more information on our Simulation for Design page, or if you want to learn more quicker, then contact us for a free demonstration and chat. Remember if you are just starting with simulation in your business, you don’t need to create a fully blown digital twin. You only need to replicate the bits that are important to your questions.