Everybody likes to preach about the benefits of seeing “the big picture”. But what does that mean, really? It appears, seeing the ‘big picture’ refers to the ability to understand a situation or concept as a whole rather than getting bogged down on specific details.
A somewhat obscure albeit related concept in a complex project or system is coverage. What is coverage, anyway?
In the software industry, the term ‘coverage’ is more frequently heard, since it is used to refer to a percentage measure of the degree to which the source code of a program is executed when a certain test suite is executed. A program with high test coverage has more of its source code executed during testing, which suggests it has a lower chance of containing surprises—i.e. bugs—compared to a program with low test coverage.
Now picture yourself playing piano, more specifically a piano with 7 octaves—like most pianos have. If you are a beginner or mid-level piano player, you will mostly stay in 2 or 3 octaves at the most, so you are basically using half of the keys the instrument offers. The rest of the keys are seldom pushed by us mortals. That’s also a way of illustrating coverage. Unless you are Martha Argerich, in which case the latter example means absolutamente nada.
Now when it comes to executing a project which is composed of a blend of many parts, components and activities, coverage refers to the somewhat unquantifiable measure of the degree at which all the relevant parts have been explored and observed—that is, interacted with—by the relevant actors. Basically, complex projects and systems describe a ‘territory’ of sorts, with its dimensions and boundaries defined by all the elements, components and tasks necessary for its proper completion. Now, are we as project managers or systems engineers touring said territory in its full extent? Are we playing all the piano keys? Or are we staying most of the time around certain centers or ‘hotspots’, only to ignore the outskirts and remote areas? It is quite typical for PMs and SEs to stay around parts of the territory—or octaves of the piano—which are more comfortable to them, more related to what they know and what they like, or what their fingers can reach. Moreover, a common problem is to pay more attention to artificial depictions or maps of said territory (models, diagrams, documents, etc.) than the territory itself.
Terra incognita or terra ignota (Latin for "unknown land") is a term used in cartography for regions that have not been mapped or documented. Similarly, uncharted or unknown seas would be labeled mare incognitum, Latin for "unknown sea". If you browse Project Management or Systems Engineering bodies of knowledge, you will see that there is not too much said about coverage. System design and complex projects can only gain the right integrity and sturdiness if all their terras incognitas are mapped, and the territory described by the maps is visited, by foot, North to South, East to West.