Final answer:
The three major source documents in job-costing systems are the job cost record or job cost sheet, materials requisition record, and labor-time sheet, which track job-specific costs for materials, labor, and overhead allocation.
Step-by-step explanation:
The three major source documents used in job-costing systems are: 1) Job cost record or job cost sheet, 2) materials requisition record, and 3) labor-time sheet. These documents are vital for tracking direct materials, direct labor, and allocating overhead costs to specific jobs. The job cost record or job cost sheet is used to compile all the costs that are directly tied to a specific job.
The materials requisition record tracks the cost of direct materials as they are allocated to a job, ensuring that the materials costs are accurately reflected. Lastly, the labor-time sheet is utilized to record the amount of time a worker spends on each job, which is essential for calculating the direct labor cost associated with that job. These documents help in the accurate costing of jobs, which is crucial for pricing decisions, cost control, and financial reporting.