What Is MES (Manufacturing Execution System)?

A Manufacturing Execution System (MES), is an information system which monitors and tracks the process of producing manufactured goods on the factory floor. The overall goal of manufacturing execution systems is to make certain that manufacturing operations are effectively executed to improve production output. That goal is achieved by tracking and gathering real-time and accurate data about a complete production lifecycle.

MES is the comprehensive system that controls all the activities occurring on the shop floor. It begins with all the various orders from customers, the MRP system, the master schedule, and other planning sources; and then builds the products in the most effective, low cost, expedient, and high- quality way possible. A comparative example occurs in the construction business where the construction team (MES) builds a tower from the architectural plans (inputs from MRP, Master schedule, etc.).

History of Manufacturing Execution Systems (MES)

Manufacturing execution systems have had quite the evolution. In the 1970s manufacturing organizations used software applications to automate their accounts. Over time, those applications were improved in order to provide the standard inventory management features. In the late 1970s/early 1980s came the MRP (Material Requirements Planning) systems, capable of material planning, material control and production definition.

AMR Research, who defined MES as a “dynamic information system that drives effective execution of manufacturing operations”, first coined the term in 1992. Early manufacturing execution system models were on-site applications, coded in a way that would represent the current manufacturing process of the organizations as-is.

Manufacturing execution systems have evolved from the simple data collection application that it was in the late 1980s into a more modern software in today’s age and time.

Core Functions of Manufacturing Execution Systems

In 1995, the ISA-95 standard was developed by the American National Standards Institute (ANSI) with the mission to provide abstract models and standard terminologies for the exchange of information between enterprise business systems and manufacturing operations systems in an enterprise.

The MES 11 model published in 1997 features the core functions of a manufacturing execution system. This model showed functions including scheduling and sequencing, maintenance and quality.

In its most current form, manufacturing execution systems core functions include:

• Data collection and acquisition

• Scheduling

• Staff and resource management

• Process management

• Performance analysis

• Document management

Benefits of a Manufacturing Execution System

A Manufacturing Execution System can deliver significant improvements in bottom line profitability, on time delivery, and better quality products. Additional key benefits of using this solution include:

• Reduces manufacturing cycle time

• Reduces or eliminates data entry time

• Reduces work-in-process

• Reduces or eliminates paperwork between shifts

• Reduces lead times

• Improves product quality

• Eliminates lost paperwork

• Empowers plant operations people

• Improves the planning process

• Improves customer service

• Reduces setup costs, wait times

• More reliable and precise sequence planning

How do MES and ERP Work Together?

Both MES and ERP (enterprise resource planning software) have the ability to work together. Since both software bring different capabilities to the forefront, using them together can help bring your business about more well-rounded results. Both software can be integrated, which can increase operational clarity and equip organizations with the ability to monitor and adjust performance against business plans. ERP knows why decisions need to be made, while MES know how to make those decisions. Both systems have their own purpose which can make them complimentary components.

Why Can’t I Just Build To The Order Schedules from ERP?

Today’s shop floor is a complex, continually varying environment. The scheduling needs to account for a level of variation that is typically beyond the scope of the planning systems- MRP, Master Scheduling and the like. MES automation considers and controls the highly critical details of a typical plant shop floor.

Causes of Variation on the Shop Floor

• Machine breakdowns

• Labor absenteeism

• Changing setup times

• Cleaning and maintenance times

• Changing delivery dates

• Quality problems

• Alternative work plans

• Alternative parts list

• Availability of transport

• Availability of quality resources

• Changes to minimize process times, setups

It is therefore imperative to place the right tools and critical information in the hands of your front-line shop floor personnel, so they can produce your products in the most optimal manner possible. A good manufacturing execution system operates on a real time basis, allowing the schedulers to react to immediate variance on the shop floor. The Manufacturing Execution System also responds immediately to help make faster decisions on such things as costing over-runs, poor quality and late deliveries. It is virtually the heartbeat for all things happening on the shop floor.

Closed Loop Integration

Yet another critical characteristic of a Class A Manufacturing Execution System, is the ability to integrate with the systems surrounding it. Not only will this eliminate the mindless re-entry of mounds of data, it will also allow the adjustments necessary to bring the surrounding systems closer to reality. For example, critical information from the shop floor is needed to update other elements of the manufacturing ERP system such as Inventory, Costing, and Procurement. Setup times may be improving with new techniques used on the shop floor, and need to be fed to the ERP system for future use. This will provide better information when advising customers of projected delivery dates on new orders, or will provide improved costing information when making pricing decisions. The shop floor information provides the reality to make the adjustments necessary to continually update the other business systems.

Shop Floor Scheduling

A high-quality manufacturing execution system will also provide the best tools for controlling the scheduling needs directly on the shop floor. The shop is a complex environment with a high level of variety. Your schedulers are therefore critical in finding key opportunities to improve your production results.

MES Scheduling Methods

• Finite Scheduling

• Queue Compression

• Visual Scheduler

• Minimum Operation Priorities

• Finite Slotting

Scheduling Methods

• F = Forward

• R = Repetitive

• B = Backward

• O = Overlap

• M = Manual

• P = Parallel

Full Functions of MES

A truly robust manufacturing execution system needs to include all the critical functions performed on the shop floor. A good Manufacturing Execution System cannot be totally responsive without the key shop floor pieces in place. The following functions should be offered at a minimum:

• Resource Allocation and Status

• Operation/Detail Scheduling

• Dispatching Production Unit

• Document Control

• Data Collection

• Labor Management

• Quality Management

• Process Management

• Exception Management

• Maintenance

• Management

• Product Tracking and Genealogy

• Performance Analysis, including Work In Progress (WIP) overviews

What Modules Does a High Level MES Include?

Core Functions of MES Systems:

• Planning System Interface

• Visual Scheduler

• eProduction/Dispatching

• Shop Floor Control

• Inventory Tracking and Management

• Material Movement Management

• Exception Management

• Data Collection

• Exception Management

• Support Functions of MES

• Maintenance Management

• Time and Attendance

• Payroll

• Human Resources

• Job Cost

• Quality

• Statistical Process Control

• Performance Management

• Document Management

• Product Data Management

• Genealogy / Product Traceability

• Product Configurator

• Bill of Material

• Engineering Change Control

• Supply Chain Management

Want to learn more? Consider these 6 questions when selecting a MES. Want to find out how a Aptean MES can help your business? Contact us today to chat with one of our experts or schedule a demo.