Modelling Systems
System modelling is the process of using models to conceptualize and construct systems in business and IT development. A model is a precise (or abstract) representation of how a system works, used to analyse and simulate answers to questions.
Simulation Systems
A simulation system imitates the real system to find out what happens under different situations and conditions, by creating models of a situation and testing to see how the models behave. Simulations are usually performed to avoid the expense or danger of making mistakes in the real system, and are used to represent systems such as traffic or pilot training.
Advantages of Modelling and Simulation
- Can be safer and cheaper than the real world.
- Able to test that a product or system works before building it.
- Can be used to find unexpected problems.
- Able to explore ‘what if…’ questions, and to speed up or slow down time to see changes over long or short periods.
Disadvantages of Modelling and Simulation
- Mistakes may be made in the programming or rules of the simulation or model.
- The cost of the simulation model, and of running several different simulations, can be high.
- Time may be needed to make sense of the results, and people’s reactions to the model might not be realistic or reliable.
What-if Analysis Using a Spreadsheet (Case Study of MS Excel)
What-if analysis is the process of changing the values in cells to see how those changes affect the outcome of formulas on the worksheet. Excel provides three what-if analysis tools: Scenarios and Data Tables take sets of input values and determine possible results (a Data Table works with only one or two variables but many values; a Scenario can have multiple variables but only up to 32 values), while Goal Seek works the other way round – it takes a desired result and determines the input values needed to produce it.
