Business cases are developed typically for big projects that require a huge commitment of resources (time, people, money). Calculations are based on best-guess revenue forecasts and cost estimates. It is written from a “fail-safe” perspective – think of everything that could go wrong, devise mitigating action plans, and cover off uncertainties as assumptions. Not only is the task challenging and energy sucking, you never really know if you’ve missed something because “what you don’t know is what you don’t know.” So, you “time-box” the effort and proclaim “Oh well, good enough”.
In 2010, Dan Gardner in this book Future Babble took a critical look at expert predictions and the psychology that explains why people believe them even though they consistently fail.
“Seminal research by UC Berkeley professor Philip Tetlock proved that the average expert is no more accurate than a flipped coin.”
Gardner based his book on current research in cognitive psychology, political science, and behavioural economics. These are intangibles that a business case cannot dollarize and frequently end up being subjectively treated in a risk assessment section.
With respect to the Cynefin Framework, the Business Case tool resides in the Complicated Domain and works well in an ordered, linear, predictable environment. It will probably continue as the approval mechanism for cause & effect solutions. Sense, Analyze, and Respond.
Just be aware that the Business Case has very little value when dealing with a Complex Domain issue where uncertainty rules, predictions are fallible, and unknown unknowns abound. Here, we must Probe, Sense, and Respond by conducting “safe-to-fail” experiments.