accounting was developed in the 1890s, labor was the largest fraction of product cost and could be considered a variable cost. Workers often did not know how many hours they would work in a week when they reported on Monday morning because time-keeping systems were rudimentary. Cost accountants, therefore, concentrated on how efficiently managers used labor since it was their most important variable resource. Now however, workers who come to work on Monday morning almost always work 40 hours or more; their cost is fixed rather than variable. However, today, many managers are still evaluated on their labor efficiencies, and many "downsizing," "rightsizing," and other labor reduction campaigns are based on them. Goldratt argues that, under current conditions, labor efficiencies lead to decisions that harm rather than help organizations. Throughput Accounting, therefore, removes standard cost accounting's reliance on efficiencies in general, and labor efficiency in particular, from management practice. Many cost and financial accountants agree with Goldratt's critique, but they have not agreed on a replacement of their own and there is enormous inertia in the installed base of people trained to work with existing practices. Constraints accounting, which is a development in the Throughput Accounting field, emphasizes the role of the constraint, (referred to as the Archemedian constraint) in decision making. The concepts of Throughput Accounting Goldratt's alternative begins with the idea that each organization has a goal and that better decisions increase its value. The goal for a profit maximizing firm is stated as, increasing net profit now and in the future. Profit maximization seen from a Throughput Accounting viewpoint, is about maximizing a system's profit mix without Cost Accounting's traditional allocation of total costs. Throughput Accounting actions include obtaining the maximum net profit in the minimum time period, given limited resource capacities and capabilities. These resources include machines, capital (own or borrowed), people, processes, technology, time, materials, markets, etc. Throughput Accounting applies to not-for-profit organizations too, where they develop their goal that makes sense in their individual cases, and these goals are commonly measured in goal units. Throughput Accounting also pays particular attention to the concept of 'bottleneck' (referred to as constraint in the Theory of Constraints) in the manufacturing or servicing processes. Throughput Accounting uses three measures of income and expense: Throughput (T) is the rate at which the system produces "goal units." When the goal units are money (in for-profit businesses), throughput is net sales