During the construction of smart factories, the MRP functionality of ERP systems proves accurate and effective in calculating total long-term demand. However, when it comes to daily, shift-based, line-specific, and material-level requirements, it faces accuracy issues.

Reasons for inaccurate material requirement allocation:

(1) MRP functionality is based on infinite capacity calculations.

(2) MRP functionality uses fixed algorithms based on predetermined conditions.

(3) MRP functionality has a single priority sequence, typically only prioritizing due dates or delivery lead times, and applies a singular material allocation rule.

(4) MRP functionality uses standard BOMs, limiting calculations to production data within fixed process routes.

Because the granularity of ERP master data management does not extend to the operation level, it cannot capture production execution data at the operational level on the manufacturing floor. Consequently, MRP functionality is unable to perform further calculations based on actual on-site production conditions.

As the sequence of on-site production changes, the input of materials and other resources also shifts in response, leading to temporary material shortages and short-term inventory buildup.

In summary, the different granularities of ERP and APS management are not causally related, nor do they address the same set of problems. Therefore, introducing an APS planning and scheduling system can help resolve the above issues encountered during smart factory construction. With the implementation of an APS planning and scheduling system, problems that MRP functionality within ERP systems cannot solve will be addressed.