I think my point is that knowing when to sharpen the saw, if the saw is sharp enough for the job, and knowing when to stop sharpening and start sawing is the ha

I think my point is that knowing when to sharpen the saw, if the saw is sharp enough for the job, and knowing when to stop sharpening and start sawing is the hard thing. The general problem here is a combination of estimating the time it will take to finish a project, and a problem of knowing what key problems dominate the final product... themselves two of the hardest things to do.