The Civilization game dependency tree
How to build a dependency tree when there is no obvious connection between the business model and an Excel model.

A long time ago I spend a lot of time playing the strategy game Civilization. For those not familiar with the game, one of its features was “advances.” Each advance brought with it certain additional capabilities and benefits. Of course, there was a requirement before one could acquire an advance, particularly a set of pre-requisites. For example, pre-requisites for the “Navigation” advance were the “Seafaring” and the “Astronomy” advances. In turn, the Seafaring advance required one to already know “Pottery” and “Map Making”.

I created an Excel worksheet that let me use Excel’s Precedent arrows to understand the optimal path to specific advances as in Figure 1. The advances are shown in red and the benefit(s) of each advance are in black, blue and green. The Excel blue arrows show the pre-requisites for the Seafaring advance.

Figure 1

While the dated worksheet may be of limited value even to Civilization enthusiasts, the technique for creating the dependency tree is unique enough to be of value to Excel consumers. What makes it of value is that the game dependencies (in the context of work this would be the dependencies in the business model) had nothing to do with what Excel considers as dependencies! Consequently, to use Excel’s Trace Precedents feature I had to somehow map the model dependency into Excel formula dependencies.

For a version in a page by itself (i.e., not in a scrollable iframe as below) visit http://www.tushar-mehta.com/publish_train/xl_vba_cases/0908%20CIV%20game%20dependency%20tree.shtml

Tushar Mehta