Which of the following is an assumption of throughput accounting?

Throughput accounting is a management accounting method that focuses on maximizing throughput (the rate at which a system generates money through sales) while minimizing inventory and operating expenses. A key assumption of throughput accounting is that direct labor costs are considered fixed in the short term, meaning they do not fluctuate with the level of production or sales within that time frame.

By treating direct labor as fixed for decision-making purposes, organizations can better analyze and manage their resources and production processes without the immediate concern of variable direct labor costs impacting their throughput. This allows for a clearer focus on maximizing throughput and managing constraints.

In the context of the other options, direct labor as the only variable cost would misrepresent the various costs associated with production. Likewise, concentrating solely on fixed costs overlooks the nuances of short-term variable costs, and suggesting all costs are variable negates the fixed nature of numerous expenses, including many overheads and certain labor costs. Thus, the perspective that direct labor costs are not variable in the short term aligns closely with the principles of throughput accounting, reinforcing the strategic emphasis on throughput maximization.