short run

Period during which only some factors or variables can be changed because there is not enough time to change the others.

When crafting your business plan, don't assume that all market participants will behave rationally. Customers, vendors, partners and competitors sometimes do irrational things. When customers or partners seem to be behaving irrationally, make sure your business model makes sense, the problem may be on your side rather than theirs. When vendors or competitors behave irrationally, it can sometimes hurt you in the short run, but will generally help you in the long run, as long as your business is sufficiently flexible to withstand the temporary irrationality.