Operating Ratio (OPEX) is a key measure of financial performance used toanalyze the efficiency of a company's management. It measures the company's profitability by comparing the total operating expenses to net sales.The operating ratio is calculated by dividing total operating expenses by net sales. The lower the operating ratio, the higher the efficiency of the company's operations.

Operating expenses are all of the costs associated with producing a product or providing a service to customers. These costs may include materials, labor, utilities, taxes, rent and other costs related to the general operation of the business. They do not, however, include depreciation or amortization expenses.

When analyzing the performance of a business, investors and analysts look closely at the operating ratio. A declining operating ratio is typically interpreted as a positive sign, indicating that a company's operational expenses are becoming a smaller percentage of the net sales. A rising operating ratio, however, is often seen as a red flag, indicating that the company is becoming less efficient due to increasing operational expenses.

While there are many benefits to using the operating ratio to measure the efficiency of a company's operations, there is one significant limitation to consider. This metric does not include debt, which may have a large impact on a company's profits. As such, it does not provide a complete picture of a company's overall financial performance.

In conclusion, the operating ratio is a valuable tool for investors and analysts to gain insight into a company's operational efficiency. It shows the total operating expenses in relation to the net sales, providing an indication of how efficiently the organization is operating. Despite its potential usefulness, analysts should bear in mind its limitation of not including debt. Additionally, it is important to consider other metrics, such as net income and cash flow, to gain an even more accurate picture of a company's overall financial performance.