1. Sales itself lacks planning. For example, the quarter ended in a few days, but suddenly found that the performance was not up to standard, and rushed to launch promotions, which caught the supply chain off guard. This is especially common in enterprises with extensive management.
2. Sales distrust demand plan. Is it good for sales not to share information? Of course not. One of the fundamental reasons why sales are unwilling to share information is the planned punishment: when "settling accounts after autumn", the plan habitually complains that the sales information is inaccurate.
3. Sales don't know the information that should be provided. An enterprise often has dozens of hundreds of products, each with N models and specifications, serving hundreds of customers. You can imagine the number of product specifications and customer combinations.