In business, even the idea that things will stay the same is just an assumption: present trends will continue only until they do not. Challenging your assumptions is vital, but there is not enough time in the world to challenge EVERY assumption. So when (and how) do you challenge assumptions?
Ask why, and then ask the why behind the why.
I have done a video about this, with insights from the theory of constraints and the 80/20 (Pareto) Principle:
The Klondike Gold Rush, fondly remembered in Edmonton every Klondike Days, shows us two paths to wealth. The obvious one – dig for gold. Also a less obvious one, which I explain in video 4 of my business strategy series:
Sooner or later your distributor will have a change of management, and the new management could ruin the business. This is a problem not just for the distributor but also for the manufacturer. In my latest business strategy video – number three in the series – I discuss the problem and some contractual terms that can help: