Income minus expenses equals gross profit. Your gross profit is the amount you use to run your company and create profits. Job-costing is how you can track the income and the costs you incur to perform each of your jobs. It’s how you get to see the gross profit you earn on each of your projects. Your perception of what you want to see from a job-costing system may be very different than another business owner’s concepts. Why? Because there is no single prescription that fits everyone’s needs.