Is it possible that changing one module can also effect other modules of your SAP implementation? How?

Is it possible that changing one module can also effect other modules

1.	Is it possible that changing one module can also effect other modules of your SAP implementation? How?
Answer» Suppose you have to create a Sales Order in Sales and Distribution (SD) module. Here, you first need to enter the transaction code(e.g., Transaction Code VA01). Next, check the stock of the item in Inventory module and check the credit limit available on Customer profile in Customer Relationship Module. It shows that all these modules are interdependent; if you customize any of these modules, it will affect the related ERP system.