The same applies to cars purchased by consumers. However, as consumer autos deteriorate over the years the depreciation is ignored, while that of capital goods is registered on the income tax forms of businesses. Limiting the definition of depreciation in a way that makes economic losses to the average man disappear into space. We live in a culture that has used complex machines for 300 years. The first patent on a steam machine, number 356, was issued in 1698.
Engineers can test, measure and specify the failure rate of mechanical and electronic devices.
A graph of the failure rate over time of a machine follows a pattern known as a bathtub curve. The curve gets its name from the obvious similarity to the cross-section of a bathtub cut lengthwise up the middle. It starts with a high failure rate dropping rapidly to a minimum. This is when the machine is new and has a high probability of manufacturing defects. The failures during this time are similar to birth defects and are also known as infant mortality.