Why do some industries have inelastic supply in the short term?

In the short run, firms cannot easily change their output levels, making supply inelastic ... Why do some industries have inelastic supply in the short term? They grow/prepare their goods years in advanced, so they cannot change their quantity supplied.

Inelastic supply means that an industry cannot change its output level easily. This is because they program or plan their output in advance, based on past sales and demand. If the demand for a good increases rapidly, the industry that produces it cannot change its output because they are not prepared for it.