A high level, comprehensive comparison between the WMS functionality of an ERP software and a best of breed WMS software. It focuses on fundamental differences and their roots. This does not include any specific ERP or WMS applications.
| ERP – Inventory Management Module | Warehouse Management Software |
|---|---|
| The inventory management functions of the ERP views of the stock from an accounting perspective. | WMS views the stock from a physical perspective. |
| The total quantity of a stock item available to sell is maintained. | WMS deals with the physical goods and tracks the product and quantities down to bin or location level. |
| ERP tracks the total quantities into and out of the warehouse, to maintain the current stock levels of each product. | In addition to the total stock quantities, WMS tracks the details of the product down to the location level, for full traceability in the physical warehouse. For example, the WMS would track whether the product was in the receiving area, had been placed into the correct storage location, had been picked or dispatched. |
| The total quantity of a stock item is maintained using various costing models. | WMS keeps track of product batch, lot, owner, and expiry etc information down to the location level. The full physical movement history of a product is available in WMS, along with the person responsible for that movement. |
| Since ERP does not keep track the inventory movements within the warehouse, it cannot optimize the process. | By keeping track of the physical aspect of the warehouse, a WMS is able to use this information to optimize the resources used in the warehouse. These resources are the space available, the material handling equipment and the staff. |
| ERP allows a single pick location to be allocated to a product that is used when storage and picking instructions are issued. | By using storage rules, taking the product class, category and dimension information into account, an optimum pick and bulk storage location can be allocated to the products received. |
| Replenishment is generated in batch and given to the user as a paper pick, it is not a real time update. | Since the system tracks the product location quantities, in both bin and bulk, replenishment instructions can be generated on the WMS. These can be issued to the warehouse workers in real time. |
| ERP works in batch mode and no real time optimization is done. | If radio frequency equipment is used or will be printed out in a batch environment, a pick sequence can be defined in the warehouse, to optimize the picker’s movements through the warehouse, ensuring that the picker walks the smallest distance possible to pick the products required for an order or a pick group. |
| ERP fulfills the order one at a time, results the picker to visit the same location many times. This decreases the operational efficiency. | The WMS is able to group the items on dispatch orders, allowing a picker to visit a location once per group of orders, rather than many times for the same group of orders. |
| ERP focuses on invoicing of sales order. | WMS focuses on correct delivery of sales order and comply with customers requirements. Using the date of entry or the date of expiry, the WMS is able to ensure that the oldest product is picked first, thus eliminating wastage due to product expiry or write-offs due to products damaged or dirtied over time in the racking. |
| ERP generally deals with a huge database and response of the system may not be instantaneous. | WMS is expected to be up 24×7 as many warehouses run 3 shifts 7 days a week. That means, there is no down time in the system. WMS is ready to work for a heavy operations and work force that has high expectations of readiness (up-time) for both the software and hardware involved. |
| ERP generally does not communicate with the real time system, material handling equipments such as conveyor, sorter, diverter etc. | WMS communicates with real time systems with quick response time. WMS serves as mission critical sub-system in the warehouse. |
WMS interfaces to the host system, to allow passing of data between the systems, so that the inventory (accounting) system and the physical (warehouse) system appear seamless to the user. Warehouse management and inventory management complement each other, both providing a different, yet useful view of the same data. By using warehouse management functionality, a business can optimize many of the aspects of stock control, ultimately providing better client service though better delivery mechanisms.