What is a simulation

Simulation using the computer is one of the modern methods used to study industrial and service processes. Simulation, which is one of the means of industrial engineering, is used to study development and investment projects. Consider the following example:

You are a responsible manager of a single machine factory. This machine takes 10 minutes to make one piece. What happens if we use a machine that only takes five minutes to produce one piece?

It is easy to answer that production will double.

What if this machine produces a semi-finished product and the manufacturing is completed in another machine? In this case, production depends on the machine, which takes longer.

Here we make an assumption that is not achieved in most cases. We assume that the runtime is a constant time. In fact, the operating time varies from one piece to another, and machine malfunctions occur randomly, and some products are defective and may need to be restarted. In addition, many operations consist of a number of operational operations – which may differ from one product to another – and transportation of raw and semi-finished materials through different transportation equipment. When we look at the production process in this realistic way, we find that there are many cases that cannot be studied with mathematical solutions, and here the value of using simulation appears.

Using a computer, we can simulate an industrial or service process. This simulation enables us to study the results of running the process for days in a few minutes and enables us to identify critical areas in the process and the effect of making changes in the work method or increasing equipment or personnel.

Simulation is not a new technique, we often use real simulation to make a decision. We may use a new method of work for a period of three days as an experiment, and then we analyze the results of performance indicators during these days in order to decide whether this method is useful or not. However, this method may cause high costs because the experience of working methods in reality may lead to many losses. In addition, some things can only be tried after investing in purchasing equipment or constructing a building. Computer simulation enables us to study these projects without risking production losses, service level problems, or losses from purchasing equipment that does not lead to the expected results.

In order to simulate a process, we must understand the process well and identify the data we need and collect it. In order to simulate the production process, we need to make the computer know the steps of the process and its component parts such as equipment, raw materials, people, and places. There are many simulation programs that enable us to enter this information in an uncomplicated manner, such as: ARENA or ProModel

Data is entered in a manner that allows the software to simulate the regular and random changes that occur in the real world. Therefore, we usually do not use the arithmetic mean to express the time of a process, but we use many different measurements for this process, and so on for other times that we use to simulate this process, such as loading times, product inspection times, and customer attendance. The ability to simulate changes in operating times, transfers, etc. is one of the main advantages of using simulation.

Before we start using the simulation model to study the production or service process, we must make sure that the model gives good results. Therefore, we start by running the model on the current situation, then we compare some of the results with the real results, and in the case of matching, we are assured of the validity of the model. For example, we may compare the daily production volume, waiting rate, inventory rate, and so on.

After confirming the validity of the model, we can use it to study many cases and compare their results. Simulation enables us to answer many questions of the type “what if….” Such as: what if this machine stops, what if we add a technical worker, what if we work at half employment, what if we add another car, what if the operating time is reduced and we Such and such a second to such a second……. Many simulation programs also enable us to watch animations that express the movement of materials, personnel, and equipment, and these graphics help us track the process and identify some weaknesses. But the biggest value of the simulation lies in the statistical data we get that helps us compare different business systems or different expansion proposals.

The difficulty of using simulation is the need for someone familiar with its use, the need to purchase a program, the effort required to collect the necessary data. On the other hand, simulation helps us to study complex problems and costly projects, which entails making sure of the feasibility of investment, access to a better method, or access to its futility. An advantage of simulation is that once we build a valid model we can use it to study many cases in a short time. For example, we may need a month or two to build a model for a complex process, then we need a few hours to study and compare many cases. We can study the operating results during a month in a quarter or half an hour.

Examples where simulation is used

Studying the best ways to reduce waiting time for customers in the supermarket (commercial market)
Studying the need to purchase new equipment or hiring new workers and knowing its impact on performance indicators

Study the appropriate planning for a hospital, factory or restaurant
Studying the method of developing an administrative process such as the process of purchasing raw materials and spare parts in a company
Simulation application areas include
Factories to study production processes
Hospitals to study the organization of working hours of doctors and nurses and to reach a good scheduling of operating rooms and the emergency room

Supermarkets To study how to facilitate customer traffic, reduce waiting times, and determine the need for customer service staff

Large sports stadiums, airports and hospitals to study the movement of individuals, patients, aircraft and waiting times

Methods for studying the ease of vehicular traffic

Great gathering places like the occasionInternational and Hajj to facilitate the traffic of pilgrims and reduce congestion and accidents and study various proposals to change some routes such as what happens in the stoning of the Jamarat
Land and sea transport operations To study the need to increase transport equipment and the return from its purchase