Manufacturing Execution Systems

Manufacturing Execution System(MES) is a vital IT function that guides Management decisions with respect to Inventory Control, Production Targets, and Purchase Decisions. It falls under the auspices of Industry 4.0 and is currently being actively implemented in the production facilities of all branded automobile manufacturers all across the globe.

What is MES ?
The IT sub-structure of a manufacturing house has multiple “Control System” in place. It can be a Distributed or Unified Control system. MES is a connector (“middleware”) that interfaces with multiple such systems and also keeps counting the amount of raw materials, semi-finished goods or to-be assembled products are getting used per hour, inventory stocks, etc.
It is implemented using a Human Machine Interface which has custom-made software installed. These softwares are tailored to suit the manufacturing capabilities of the production line. Such software are designed keeping in mind the business objective of the firm which can be either “Quantity – large number of vehicles per day” or “Quality – each vehicle produced is very costly and hence highest standards are adhered to”. MES software needs to be fast. The average takt-time of a production line hovers about “60-90” seconds.
As MES interfaces with a lot of Web-Systems and localized systems in REAL-TIME, it needs to be lean and agile. MES handles the basic assembly functions like “Part Marriage”, “Assembly Quality Checks” as well as more complex functions of Order Production to from Order Pipeline and sending the m-BOM to the suppliers to supply requisite parts.

Why use MES ?
A typical automobile shop floor churns out 300-400 vehicles per shift to satisfy demand and maintain profitability. Each modern automobile has thousands of parts that need to be assembled. Thus keeping physical or EXCEL records and ordering goods in real-time poses a business challenge as an operation is scaled up. Hence MES software comes in handy to maintain track of used inventory, manufacturing takt time and other scenarios. Also in case any production line comes to a halt either due to technical fault or manual intervention by the operator MES systems have the capability to alert Line Managers and other relevant authorities to rectify the issue and take relevant decisions.

How is MES ?
MES softwares are largely tool based Tools include Apriso, GE Proficy, Cimplicity and other in house softwares provided by OEMs. These tools allow custom coding to satisfy the business need. Coding languages used are Java, MS.Net, VBScript and some other languages. As multiple functionalities are implemented clashes between two functionalities are common and proper testing is required to smoothen out the irregularities that occur over time. As MES interfaces with multiple web-based systems, it requires a lot of Java and MS.Net custom coding and regular update package deployment.

Problems and Cautions: It is easy to write macro code problems that exist with the very nature of the VB Script Language. Thread handling is an issue as multiple instances running parallelly create race conditions. It is the developer’s onus to understand the bigger picture and fashion his code accordingly.
Another major issue generally faced is Database interfacing. Due to the high speed of data writing, modification and multiple instances trying to modify the same table or using the same Stored Procedure leads to deadloss and memory leakage. Best practices of Stored Procedures need to be followed for minimizing the number of stored procedures and maximizing the scope of each to satisfy various needs. The exception handling of both SPs and VBScript codes need to be very strong to enable quick identification and debugging in case of issues.