Every firm faces limited resources and limited demand for each product. These limitations are called constraints. The theory of constrains recognizes that the performance of any organization is limited by its constraints. The theory of constraints of then develops a specific approach to manage constraints to support the objective of continuous improvement. According to TOC, if performance is to be improved, an organization must identify its constraints, exploit the constraints in the short run, and in the long run, find ways to overcome the constrains.
Basic Concepts
TOC focuses on three measure of organizational performance: throughput, inventory, and operating expenses. Throughput is the rate at which an organization generates money through sales. In operational terms, throughput is the difference between sales revenue and unit-level variable costs such as materials and power. Direct labor is typically viewed as a fixed unit-level expense and is not usually included in the definition. With this understanding, throughput corresponds to contribution mar-throughput. Operating expenses are defined as all the money the organization spend in turning inventories into throughput. Based on throughput, minimizing inventory, and decreasing operating expenses.
By increasing throughput, minimizing inventory, and decreasing operating expenses, three financial measure of performance will be affected: net income and return on investment will increase, and cash flow will improve. Increasing throughput and decreasing operating expenses have always been emphasized as key minimizing inventory, however. In achieving these improvements has been traditionally regarded as less important than throughput and operating expenses.
The theory of constraints, like JIT, assigns inventory management a much more prominent role than the traditional viewpoint. TOC recognizes that lowering inventory decreases carrying cost and, thus, decreases operating expenses and improves net income. TOC, however, argues that lowering inventory helps produce a competitive edge by having better products, lower prices, and faster response to customer need