If the company is high in the tech arena, then their products can out date in relatively short amount of period. Sometimes, components for older products need to comply with new standards or requirements. If the sales for that product is already decreasing, then the company may not invest more time, money and man hours on updating the necessary compliance requirements on them. Even natural disasters can have a huge impact. In some places, it has destroyed manufacturing plants and slowed production. Post that, it makes procurement very difficult for legacy products. Also, another example could be the supplier going out of business and no other supplier is available who makes a suitable component. In such cases, a product can be considered for obsolescence. This way a company can streamline its manufacturing operations.