Commercial software isn't generally an artisanal crafting process. If you're a programmer who solves variations of a problem, analogous to a carpenter building

Commercial software isn't generally an artisanal crafting process. If you're a programmer who solves variations of a problem, analogous to a carpenter building varieties of cabinets, then you have parameterized tools. When the client asks for maple instead of oak, you don't pull out a maple board and start sawing. You'd just go to your cabinet_template.yaml file and change material=oak to material=maple. You don't have to estimate how long it will take to build the cabinet because it's already done, you just ran build_cabinet.sh.