4.2 Simulation Simulation is a modelling technique that is often used in capital investment appraisal, especially as part of scenario planning.
Simulation involves the construction of a mathematical model and has the following features:
§ It produces a range of possible outcomes and their probability distribution.
§ It is a relatively easily understood technique.
Monte Carlo simulation, which uses statistical simulation methods, is a simulation method that is capable of addressing the most complex applications. It involves:
§ the constant random generation of values for uncertain variables to simulate a model
§ the consideration of all possible combinations of variables (unlike sensitivity which considered the effect of changing just one variable at a time).
Monte Carlo simulation can include all random events that might affect the success or failure of a proposed project, as identified in the scenario planning. For example:
§ a competitor appearing
§ changes in consumer taste
§ changes in inflation or exchange rates, etc.外语学习网
There are major drawbacks of simulation.
§ It is not a technique for making a decision, only for obtaining more information about the possible outcomes.
§ Models can become extremely complex, particularly where dependent probabilities are involved.
§ Thus the time and costs involved in their construction can be more than is gained from the improved decisions.
§ Probability distributions may be difficult to formulate. |
发表于 2012-2-23 17:09:42
