In every decision support system, we use simulation which is “theprocess of designing a model of a real system and conducting experimentwith this model for the purpose of either understanding the behavior of thesystem and or evaluating various strategies for the operation of the system”.It helps us to make confident, evidence based decisions that helps us toimprove the organization’s efficiency and profitability, and also, it is used toconduct What-if analysis. In this document we will discuss the simulation’scharacteristics, advantages and disadvantages.To begin with , simulation allows us to do many things , first of all itallows us to display the complex system in a detailed way , second of all ,analyze the system, third of all, we use the model to foresee future behavior ,last but not least , we can use simulation to describe the behavior of systems.Lastly, it allows us to form assumptions or theories.Simulation has a lot of characteristics, the first and the most importantcharacteristic that it reflects the real world but it does not represent it,another characteristic that is a mechanism used to manage experiences .Also, facilitated more than any other method, last but not least, it isdescriptive rather than normative, and the last characteristic, it is useful tosolve complicated problems.Last but not least, Simulation can be conducted in 9 steps, beginning withfirst step which is; problem definition where you clearly outline the problemor the opportunity within the process that you want to conduct the simulationbased on, and where you make sure to determine if simulation is theappropriate tool for the problem under investigation. The second step isproject planning, where you take the scope that you established before andbreak it down into manageable tasks to start assigning the appropriateresources to the, milestones time schedule and resource plan should beestablished as well, then you define the system, where you clearly outlinesthe components of your system or process ( how many entities, theirstate..etc) and the performance measures as well as the type of input data andthe output data of the process. The forth step is formulating the modelwhere you understand the relationships between the components and howthe whole process acts and functions , then you test and validate the model toensure that the model behaves as intended and there is no significantdifference between it and the real process or system ,after you test themodel you have to design the experiment where you test the set of scenariosthat help you identify which type of input have impact on outputs and thetarget level of these inputs to achieve the goal determined before DOE(design of experiments) helps me to compare the alternatives, to maximizeor minimize a target output as well as to try to reach optimal output in andDOE I identify the factors (inputs), levels and the response (outputs) . lastbut not least you have to conduct the experiment after you design set ofexperiments you choose amongst them the best and most suitable for yoursituation. Then you evaluate the results according to my process to makesure it achieves the goal that you set before and the last step is ,documentation and implementation which consist of written reports,presentation, forms the result and the implication of the study.Simulation has numerous advantages especially in today’s advantages,we highlighted in our presentation the top of these advantages that includes;the first advantage is simulation is descriptive rather than normative ; whichdescribes the situation or the problem and graphically shows therelationship amongst various components however it do not indicate anycourse of action. Also, it can be used to trial and error with little expense andmore accuracy; it allows the decision maker to try multiple of factors in thestudy to see their effects with little expense and more accuracy, becausehe/she is able to see the results and evaluate it. Moreover, it allows themanager to experiment to determine the significant factors or inputs and howdo they affect the results; through experiments he/she can determine the keyinputs that any slight change in them affects the whole result and thus focusmore on keeping them stabilized, maximized or minimized. In addition, itproduces performance measures and also it is the best for handlingunstructured problems simulation is the most appropriate model to handleunstructured problem in business and in today’s complex environmentsimply because it allows the representation of the inputs with theirrelationships and it reflects the real word system or process.Despite the advantages listed above simulation has many drawbacksthose are, simulation can be costly and time consuming: simulation projectscan be costly simply because many simulation models must be built fromscratch in most of the time, also multiple type of simulation models must bedeveloped during the project life cycle which makes them not applicable incomparing to scope set for many of the projects. Also, an optimal solutioncannot be guaranteed; because it is a descriptive model it may be hard toreach an optimal solution because you simply can’t experiment all thepossible alternatives out there. And the last disadvantage is that Simulationsoftware sometimes requires special skills: because of its complexity thesimulation told requires a deep understanding and knowledge and requiressometimes a programmer to be involved thus, they need special skills to beable to conduct a simulation project fully in any organization.To conclude, simulation is an effective technique for imitating an existingor proposed process, it enables us to build a visual representation of yourprocess , so you can easily make changes and see how exactly they willaffect the process in real life without any risk to your current performance ,which helps you to solve complex problems or costly to experiment with inreal life . In addition, the characteristics of simulation. Also, the advantagesand disadvantages to simulation.