Return benefit from effort has a diminishing returns response. There is also a threshold effort before there is any return. Consider building a piece of furniture. Effort may start with buying the...

Return benefit from effort has a diminishing returns response. There is also a threshold effort before there is any return. Consider building a piece of furniture. Effort may start with buying the wood, stain and varnish, and sharpening and aligning the cutting tools. This effort is necessary, but so far there is nothing to sell; there is no benefit to the carpenter. After assembly, light sanding and one coat of finish may make a salable item; but more sanding and another coat of finish makes it an excellent item, increases perceived value to the buyer, and willingness to pay a higher price. Additional carpenter effort beyond excellence moves the item toward perfection, but doesn’t increase value over something already excellent. Often an S-shaped relation is used to relate value to effort. The logistic relation is one, V = a 1 + e^{−b E−c}, where “E” represents the time or effort invested and “V” the value. You probably have 20 things that you are working on and only 100% effort to give. If you work totally, you don’t eat or sleep, which are necessary functions to be able to invest energy in any project. As you personally seek to optimize life outcome, what are DVs, OF, and constraints? For simplicity and clarity, only consider three projects.