Disadvantages are as follows:

1. Data security: As important data such as customer information and sales records are involved, personal privacy and business secrets should be protected when using such systems, and corresponding measures should be taken to prevent the risk of information leakage.

2. Insufficient technical support: If you encounter software failures or other technical problems, it may take a long time to solve them and resume normal operation.

3. High cost: It usually costs a certain amount to purchase and maintain this kind of software, and other related costs (such as training fees, hardware equipment updates, etc.) will also occur.