| Financial analysis: |  |
| Environmental impact analysis: | --- |
| Waste management/P2: | |
| Environmental cost listing/database: | --- |
| Cost estimation: | --- |
| Alternative product/process comparison: | --- |
| Financial analysis: | |
| Environmental impact analysis: | --- |
| Waste management/P2: | |
| Environmental cost listing/database: | --- |
| Cost estimation: | --- |
| Alternative product/process comparison: | --- |
| Cost control | --- |
| Resource control | --- |
| Estimating control | --- |
| Schedule control | --- |
| Scope control | --- |
| Risk control | --- |
MOUSE is a Monte Carlo-based simulation system that is designed to deal with uncertainties in static mathematical models, such as a set of environmental engineering calculations. Unlike deterministic algebraic models, stochastic models contain input variables in the form of probability distributions that reflect the uncertainty about their values. There are different approaches to solving algebraic models that involve uncertainty. MOUSE uses a form of Monte Carlo simulation known as Model Sampling. This method is an attempt to address problems associated with traditional approaches to uncertainty. These include an inability to show a combined net effect of changes in all variables or the likelihood of various changes occurring together. Model Sampling involves the following:
After the correct input of every equation, AutoMOUSE gives users the option of entering more equations or proceeding towards analysis. When equation entry is complete, users have to specify the nature of distribution and parameters for all stochastic variables, with the help of a menu. For example, users can select a normal probability distribution and specify a certain mean and standard deviation. If it is not clear what probability distributions should be used, the Interactive Modeler for Probability (IMP), which is a MOUSE utility program, can perform the following functions:
MOUSE possesses all the features for substantive uncertainty analysis, such as built-in probability distributions, plotting and graphing capabilities, sensitivity analysis, and interest functions for cost analysis.
| Raw material acquisition | --- |
| Manufacturing stage | --- |
| Use/reuse/maintenance | --- |
| Recycle/waste management | --- |
Not applicable.
| Conventional | --- |
| Potentially hidden | --- |
| Contingent | --- |
| External | --- |
Not applicable. There are no cost categories or cost summary reports generated. MOUSE can be used to analyze a set of equations related to any type of project or cost types.
The system is not designed for cost estimation. However, it can be used to incorporate the risk element, thus improving the accuracy of various cost estimates, which can also include liability costs and less-tangible costs.
In its third and current stage of development, MOUSE can be used by individuals with little or no knowledge of computer languages or programming or simulation. Yet it can be equally beneficial for experienced users. Unlike earlier models of MOUSE, the current version does not require users to write a FORTRAN program or perform other cumbersome and error-prone tasks. Using a program called AutoMOUSE, the current version actually writes all of the MOUSE program. Users only have to input the equations of the model and answer queries regarding the output desired. They also specify the probability distributions for uncertain (stochastic) variables in the model and arguments for these distributions. AutoMOUSE operates in two modes: nonexpert and expert mode.
MOUSE has many advantages over other major approaches to conducting Monte Carlo simulation analysis on algebraic models. The other approaches use general purpose computer languages, such as FORTRAN; general purpose simulation languages; and spreadsheet Add-on programs.
AutoMOUSE makes preliminary and detailed checks for errors during equation input and editing. The scans check for syntactical and also logical errors(using a trace). The model equations can also be entered via a file prepared with any ASCII text editor. In the expert mode, users can make other choices such as specifying the number of iterations in the Monte Carlo simulation, performing sensitivity analyses for all or any of the independent variables and changing the random number seed.
Although it is available commercially, the system was not designed for that purpose. Hence, little user support (as offered by private vendors) is provided. Queries can be directed to the EPA Risk Reduction Engineering Laboratory.
Each equation is limited to three lines. One of the disadvantages of MOUSE is that the programs have to undergo preliminary processing, such as compiling and linking, before they can be run. Advantages include its flexibility and ability to run complex standard simulation routines. AutoMOUSE is limited to a maximum of 200 variables, but it is stated that this does not pose a problem for most models.
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Generation of financial indicators
Net present value (NPV)
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Payback period
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Internal rate of return (IRR)
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Benefits cost ratio
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Other
--- Ability to include environmental costs
User friendliness and flexibility
User-support
Limitations
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