An Enterprise Resource Planning (ERP) system is often thought of as the only system needed to manage and automate the back office functions of an operation. But, truly effective use of ERP software requires an integration of a number of tools that oversees all facets of an operation: product planning and costs, product development, HR, manufacturing, sales, marketing, inventory management and distribution. One important tool is a Manufacturing Execution System.
You can look at it this way: ERP creates and manages a basic plant schedule and focuses on analysis of this plan against what actually happened in the past. Therefore, the ERP overview applies to longer time horizons such as months, weeks and days. It is the macro view of an operation that looks down into and organizes the details. MES, on the other hand, drives the manufacturing operation in real-time -- examining what is happening on the shop floor in minutes, hours, and shifts. It is the micro view that collects data on every aspect of the manufacturing process, such as alerting floor supervisors in real-time of missed opportunities or problems on the floor.
Let's take a look at the value MES brings to an operation:
Both ERP and MES are reactive systems, responding to what has happened in the past. To add an additional, proactive, tool that integrates into and adds value to the ERP system, an Advanced Planning and Scheduling (APS) module can be considered. Designed to optimize the scheduling process, APS takes input from various departments, compares them, and offers the manager an opportunity to create simulation models and projections.
See how integrating ERP, MES, and Advanced Planning and Scheduling (APS) creates a closed loop between planning and operations. In this video, PlanetTogether APS is shown working alongside ERP and MES to turn real-time shop-floor data into optimized schedules, clear priorities, and faster responses to exceptions. It’s an ideal next step if you’re rethinking your ERP-only strategy and want to understand how MES and APS connect planning, execution, and continuous improvement in your manufacturing operations.
In this article, you’ve seen that ERP is often treated as the only system manufacturers need—but in reality it is just one part of a complete operations stack. ERP provides the macro view of orders, costs, and long-range plans over weeks and months. MES provides the micro view, capturing real-time events on the shop floor in minutes, hours, and shifts and alerting supervisors to issues and missed opportunities.
Both are powerful, but they are also largely reactive: they record what has already happened. To close the loop between planning and execution, you need an Advanced Planning and Scheduling (APS) layer that uses data from ERP and MES to optimize the schedule, run simulations, and give operations a proactive way to manage capacity and constraints.
Our white paper, “WHY ERP ALONE IS Not the Answer,” explains exactly where ERP systems reach their limits and how APS fills the planning and scheduling gaps. It shows how adding APS on top of ERP (and alongside MES) gives manufacturers the decision-support and optimization capabilities they need to compete.
In this guide, you’ll learn how to:
If you’re recognizing the limits of an ERP-only approach and want a practical roadmap to a more integrated, future-ready operations stack, this white paper is your next step.