Estimating Drafting and Engineering Time

I'm not too sure of many other industry-specific forums, and I feel like this is also pretty specific to how Microvellum is used, so forgive me if this is off-topic, but I needed to ask someone:

How do you estimate the amount of time it will take a drafter or engineer to complete a task?

Drafting a job, do you estimate based off of the contract value, product types, do you use a formula or just wing it?

Engineering a job for production (VIF dimensions, AAN redline changes, hardware changes, that sort of thing)- again, do you have a formula, and if so, what is it based off of?

I need a good way to estimate the amount of time it will take to complete these tasks for each job with relative accuracy without sacrificing a lot of time figuring this number for each job. Is there analytical data baked into Microvellum that can help here (I don't think there is, but it's worth asking)?

Thanks in advance!