"Guesswork" refers to making an estimation or assumption about something without having solid evidence or knowledge. It involves using one's intuition or speculation to come up with an answer or solution. Full definition
It would take a lot of guesswork out of this recipe if you could be more specific on ingredient amounts. (annmariegianni.com)
In the same way that brand standards dictate a color palette to a designer, or coding standards dictate naming conventions to an engineer, management standards take guesswork out of the equation, informing every manager at the organization what to do, and when. (entrepreneur.com)
The carrier has held up surprisingly well for the two years it's been in semi-frequent use, particularly considering there was no pattern but a lot of guesswork involved in making it. (soulemama.com)