When making or editing professions you can set priorities for each category of tasks for the each specific profession. Below is a list of the task categories:
Workshop: Covers any jobs at Workshops.
Farm: Harvesting, planting and tilling at areas designated as farms.
Groves: Harvesting and planting at areas designated as groves.
Pasture Feeding animals at areas designated as pastures. Also handles the task of pasturing animals.
Tinker Tinkering at the Tinker Bench.
Hauling Transportation of goods to Stockpiles.
Agriculture Harvesting (including fruits from trees), planting trees, felling trees not in a grove, brewing at distillery and cooking at kitchen.
Hospital: Caretaking of hospital patients and healing injured patients with bandages.
Build: Building floors, walls, furniture, storage and workshops.
Mining: Mining terrain and digging stone, ores and gems.
Mechanic Jobs at the Engineer and Machine Shops and anything involving mechanisms.
After looking at their priorities gnomes take the closest job they can currently complete. They then path to the required tools, components and the job itself. When looking to see if they can complete a job, they consider whether they have the required skill for the job and whether the required components and tools are available and within reach. They will not look at other jobs and determine if accepting that job will affect other pending jobs.
Gnomes in squads will do their squad duties before accepting jobs. After equipping, if their squad isn't on guard duty, patrolling, or training they will perform jobs.