Anyone can perform an analysis by hand. As the complexity of that analysis rises, though, so does the need for a computer-based process improvement tool. Spreadsheets can run many complex calculations and gauge the operational status of most systems, but leaning on average numbers to represent arrivals, activity times, and resource availability is like using a spoon to dig a canal. Simulation gives you the equipment for the complex projects.
Accurate depiction of reality
With simulation, you can build in randomness through properly identified probability distributions taken straight from your study data.
For example, while an assembly may average 10 minutes, special orders can run as long as 45 minutes. Simulation captures interdependence through arrival and service events and tracks each one individually. Order arrivals might place items in two locations at once, yet a single worker can only handle one item at a time. A spreadsheet quietly assumes that operator is available in both places simultaneously, and the answer it gives you is wrong.
Advanced optimization techniques
Optimization methods such as linear, goal, and dynamic programming are valuable when you want to maximize or minimize a single element, for instance cost, utilization, revenue, or wait time. The catch is that they limit you to that one element, often at the expense of secondary goals, and they do not allow randomness in the input data. Forcing you back onto average process times and arrival rates produces misleading results. Simulation optimization lets you weigh many elements at once and track system performance across activity time, arrival and exit rates, costs and revenues, and utilization. Optimizing several elements together gives you the information you need to make accurate decisions and apply more effective solutions to the whole operation.
The optimization module in ProcessModel is a built-in capability for running optimization directly on your simulation models. It accepts the parameters you control and might change, such as the number of operators or the priority of events, and it lets you define objective functions to minimize or maximize specific model elements through weighting factors assigned to each one. Once those items are defined, the module runs a series of tests across multiple scenarios to seek the optimal solution. The output details the optimized result and reports the key factors in both text and graphic form.
Insightful system evaluations
Simulation tracks events as they occur and gathers all of the time-related data for reporting. The picture you get of system operations is far more complete than other techniques can offer.
With static methods such as queuing theory and spreadsheets, you learn the average wait time and the average number of items in a queue, and there the trail ends. With simulation you also get the wait time, the number of items, minimum and maximum values, a confidence interval, the data distribution, and a time plot of values. It is far more useful to know that the queue exceeds 10 items only 5% of the time than to know that 2 is the average number waiting.
Static techniques also restrict you to average parameters, and those averages can mislead you into seeing an over- or under-capacity situation that is not really there. A spreadsheet assumes production orders move unconstrained when, in reality, an operator has to make the move happen. The result is an inaccurate capacity estimate.
Scheduling capabilities
Simulation lets you experiment with a system and watch how it behaves under particular configurations of inputs, resource arrangements, routing rules, downtimes, and shift schedules. With the basic model elements in place, you can test alternative production schedules across multiple scenarios and carry out many other scheduling tasks. To its credit, simulation allows real-life behavior such as randomness and interdependence, in contrast to pure scheduling packages that let activities proceed unchecked at a fixed rate.
Animation
Animation is one of the most powerful aspects of simulation. The feedback it provides confirms that the model behaves correctly. If the animation shows no arrivals at an order processing area during the middle of the day, for example, the arrival data may be off. Animation also helps you spot bottlenecks and isolate which system elements you could change to get better results.
Animation is an excellent presentation and training tool as well. Simulation animations sell new ideas quickly and clearly, and they show the effect on an entire system when duties are performed on time and accurately.
Does simulation pay for itself?
Like any project, a simulation project asks you to weigh what you spend against what you gain.
Expenditures
- Software acquisition
- Training or startup time
- Labor to capture information, build and analyze the model, and develop the future process
Hard-dollar savings
- Lower capital expenditure, higher utilization of an existing facility, and a reduced net cost
- Proper employee assignments that prevent unnecessary hiring
- Accurate, insightful facility planning that eliminates rework costs
Soft-dollar savings
- Facility rearrangement or reassignment of duties that increases productivity
- Reduced wait time that improves customer satisfaction
- Accurate system depiction that ensures valid decision-making information
- Lower training costs for new hires
Labor savings
- Rapid, accurate model development that establishes time and cost data quickly
- Greater understanding of the actual process, which improves employee education
- Coordinated simulation projects that improve teamwork and communication
- A clearer sense of “how I relate to the rest of the system”
Intangible benefits
With simulation you can surface problems that stayed invisible in the past, opening up savings that older methods never reached. How much you save depends largely on how you select projects, but a well-chosen project returns many times its investment. One simulation user identified and tested an additional 10% saving from suggestions raised in a management meeting. Would you not like to be able to test the validity of a suggestion on the spot? To see the approach in action, take a look at the benefits of business process simulation or explore plans and pricing.
