GoldSim User Conference San Francisco, CA October 25-26, 2007

1. GoldSim Tutorial: Model Building Tips for Organizations Creating Models that can be Easily Shared and Reused GoldSim User Conference San Francisco, CA October 25-26, 2007

2. Overview • Why Would I Want to Make My Models Easier to Share and Reuse? • How Can I Make My Models Easier to Share and Reuse? • Discussion of Modeling, Documentation, and Style Conventions • Creating a Model Library

3. Why Would I Want to Make My Models Easier to Share and Reuse? • Models can be built faster (and in organizations with many GoldSim users, much faster) • Consultants should be prepared to charge and end-users should be prepared to pay for value, not time • Models will have less errors • Modules can be extensively tested • Models will become more realistic • Time can be spent on improving models and making them better instead of reinventing the wheel • Models that can be easily shared and reused generally are also models that are very transparent • Transparent models are more likely to actually be used to support decision-making

4. How Can I Make My Models Easier to Share and Reuse? • Build transparent models • see Tauxe and Catlett presentation • Be consistent • Individual users should use a consistent set of modeling, documentation and style conventions • Organizations with multiple users (or companies with multiple GoldSim consultants) should agree upon, document and enforce a consistent set of conventions

5. Creating a Set of Conventions • There is no one correct way to build a good model • However, models must use a consistent set of conventions to be good models • Models with multiple styles and sets of conventions are very difficult to use • Within an organization, this will require meetings and negotiation • Types of conventions to implement: • Model structure and organization • Naming conventions • Documentation conventions

6. Creating a Set of Conventions (cont.) • Do not over-specify the conventions • If the rules are too rigid, they could have the effect of making some models less transparent • The more restrictive the rules, the higher the likelihood that they will be ignored • Let’s examine some examples of the types of conventions you might specify

7. Conventions for Model Structure and Organization • Top-level organization of models

8. Clear Model Title Containers separating inputs and key results from Model Brief model description However, keep in mind that often, a picture is worth a 1000 words

9. Conventions for Model Structure and Organization • Top-level organization of models • Use of Container protection

11. Conventions for Model Structure and Organization • Top-level organization of models • Use of Container protection • Cloning Data elements

12. Cloning Data Elements in a Model

13. Conventions for Model Structure and Organization • Top-level organization of models • Use of Container protection • Cloning Data elements • Use of cloned Containers

14. Using Cloned Containers Localized Localized A B A B Clone2 Clone1 X = f(A,B) X = f(A,B)

15. Conventions for Model Structure and Organization • Top-level organization of models • Use of Container protection • Cloning Data elements • Use of cloned Containers • Use of hyperlinks as navigational aids

17. Documentation Conventions • Consistent set of documentation so that people always know how to dig deeper into the model • Things to address: • How input data is documented (e.g., notes with hyperlinks) • Use of Descriptions and Notes • Use of Text Boxes and Graphics • Use of Hyperlinks • Use of custom images for elements • Use only at high levels • Create an image library

18. Naming Conventions • One of the easiest ways to build consistent models that can be shared • Examples: • Inflow_xxx • Expense_xxx • Volume_xxx • This not only makes the models easier for others to understand, but it should help you better understand and navigate your own models

19. Rules for Building Dashboards • Create a template that everyone uses • Specify style guidelines (e.g., documentation, navigation)

20. Developing a Model Library • Facilitates rapid development and sharing of models • Leverages prior work and maintains consistency • A “gatekeeper” should be identified to make sure only high quality models are posted • There are intellectual property (IP) issues that must be considered • We will discuss this in the Panel Discussion

21. Final Words • Building models that can be shared and reused has very clear advantages • Doing so requires creation of some standards and procedures (none of which are onerous) • I have yet to see this happen in any organization