1. Changes in market demand: Market demand for a certain product may change over time. If sales decline to the point where it is no longer economically feasible, the manufacturer may decide to discontinue production to avoid losses.

2. Technology updates: New technologies and designs may make old products no longer competitive, and manufacturers may decide to discontinue old products and introduce newer products.

3. Cost control: Manufacturers may face pressures such as rising raw material costs and increased labor costs. In order to maintain profitability, they may choose to discontinue production of certain products.

4. Regulatory requirements: The production and sales of products may be subject to various regulations and standards. If the product cannot meet the latest regulatory requirements, the manufacturer may stop production to comply with regulatory requirements.