The great successful men of the world have used their imaginations, they think ahead and create their mental picture, and then go to work materializing that picture in all of its details, filling in here, adding a little there, altering this a bit and that a bit, but steadily building, steadily building. Robert Collier

Unit 17 Overview

Congratulations! You’ve almost completed the GoldSim Course.  As we noted in the first Unit, the purpose of this Course was to teach you the fundamentals of dynamic, probabilistic simulation and GoldSim.  And if you took the time to work through the Examples and Exercises, we should have accomplished that.

Understanding these fundamentals is an essential first step toward building complex models.  However, even if you feel comfortable using GoldSim now, this certainly will not make you an expert (or even a proficient) modeler. Building realistic and useful models requires three things:

1.  An understanding of the fundamentals of simulation and the use of one or more tools (e.g., GoldSim) that you can use to build a model.

2.  A conceptual and quantitative understanding of the specific system you are trying to model.

3.  The ability to evaluate a system, conceptualize it in a generalized (and often abstract) way, and subsequently represent the features, processes and events defining the system quantitatively at an appropriate level of detail.

This Course has focused entirely so far on only the first item. 

The second item is obvious. If you want to model a system, you must first have a conceptual and quantitative understanding that of that system. It should be noted, however, that this does not mean you need to be an expert on all of the details of that system.  In fact, for many complex systems, no one person will be an expert on all aspects of the system, as the model may involve sub-systems that require a wide range of expertise (e.g., ranging from engineering to economics to political science). The best modelers, however, are able to ask the right questions, obtain information from subject matter experts, and integrate this information into a cohesive and representative model.  This, in fact, leads into the third item.

Whereas the first item is something you can obtain through study and practice (e.g., taking a Course and using a tool), and the second item is something you can obtain largely through access to subject matter experts (or perhaps technical literature), the third item, unfortunately, is something that for the most part cannot be easily learned from a book. The ability to evaluate a system and subsequently integrate and represent the features, processes and events defining the system in an appropriate way into a quantitative model takes trial and error, practice and experience, and perhaps most importantly, interaction with and feedback from experienced modelers. How detailed should the model be?  Which processes can be ignored and which need to be included? How can a particular process be represented in a generalized and robust way?  These are the kinds of questions that will need to be addressed when building a model, and the questions and answers will be different for each model. Learning how to answer these questions requires practice and experience, and the more experience you have, the better you will be at it.

In this final Unit, we are going to briefly address items 1 and 3.  In the first part of the Unit, we will continue to discuss some of the features and capabilities of GoldSim:

      As we mentioned in Unit 1, although this Course covered all of the key features and capabilities of GoldSim, a number of advanced features were not covered at all. With what you have learned in this Course, you will be able to tackle many complex problems.  However, GoldSim provides some additional powerful features that you will want to use once you become proficient with the software.  Rather than discussing these features in detail, however, the goal here is simply to make you aware of them, so that once you are more comfortable with GoldSim, you can start to learn about and take advantage of them.

      GoldSim has a number of specialized extension modules that can be used to model specific types of problems. Again, once you become proficient with the software, you will likely want to learn about these.  Rather than discussing these modules in detail, however, the goal here will simply to describe in general terms what they can be used for and to make you aware of them, so that once you are more comfortable with GoldSim, you can start to learn about them.

In the last part of the Unit, we will provide some general guidance regarding the third item above (learning how to be an effective modeler). We will start by providing a discussion of the overall modeling process, and will close with a list of resources you can take advantage of to start to become an expert modeler.