What's Your Game Plan for Implementing MES?

To reduce both short- and long-term risk, interfaces should be kept as simple as possible, and the amount of data transferred between them should be kept to a minimum. When using interfaces, even standard ones, follow the methodology laid down by industry standards. The ISA-95 Standard Enterprise - Control System Integration [1] provides a framework within which a system in an integrated solution should perform certain functionality, together with the key data exchange that should occur between interfaces.

The Devil’s in the Details

Apart from the functionality and software systems that are used in an MES implementation, consideration should also be given to the infrastructure required. For instance, on what terminals are the end-users going to perform their tasks? Do such terminals exist? What is the existing network availability? Is there an existing dedicated manufacturing or automation network?

Many MES vendors now support the use of wireless devices such as tablet PCs or PDAs to run their applications, and this can be highly beneficial when end-users are in an environment where mobility is required, as is the case with mobile equipment. Through the use of such devices, operators can have the mobility and flexibility of a paper-based system while benefitting from MES functionality.

Moving from a paper-based interface to an MES eliminates data entry and other errors and makes KPIs available, and readily visible, to managers (such as this one), as well as operators on the plant floor. But certain tasks, such as signing off on batch records, take on added significance in an electronic environment, and training must address this fact. Photo courtesy of ProsCon, Ltd.

While these issues may seem relatively trivial to deal with at first, they can prove to be major stumbling blocks if not properly thought through. If manufacturing activities are performed in a clean or sterile environment, then the impact of adding more network coverage, such as cabling and network points, can cause major disruption to operations. Furthermore, the cost of placing industrial-rated PCs and appropriate enclosures required for real manufacturing environments must also be considered. Finally, if the MES is a fully integrated system with interfaces to automation and business systems, the whole architecture must be carefully considered, from both a performance and security perspective.

Traditionally, automation systems have largely been stand-alone, either in the form of a Programmable Logic Controller (PLC) and Supervisor Control And Data Acquisition (SCADA) package, or a Distributed Control System (DCS) system with little or no connectivity to external systems. Consequently, performance or security issues have not arisen in the past. With an MES system, however, there is connectivity from control devices to the Internet, so security is an important consideration.

The situation is compounded further by the fact that it is much more difficult to patch “validated” control systems. In some cases, automation vendors specifically prohibit the use of anti-virus software on their systems.

As with the interfaces, industry standards and best practices are starting to emerge, such as the ISA S99 Manufacturing and Control Systems Security Standard [2]. Such standards address the connectivity required for data flow between systems, while at the same time providing sufficient security safeguards around automation systems and these should be factored into an implementation strategy.

Phased in vs. Big Bang?

If multiple MES modules are being implemented, the question arises as to whether or not to adopt a gradual, phased approach versus a ‘big bang’ implementation. A phased approach allows one to use fewer project resources over a longer period of time. This can be an important consideration if experienced, cross-functional resources are hard to come by.

Furthermore, a phased approach may shorten the time to benefit for key modules. Other aspects of phased approaches may be to deploy the MES solution on one line or train, and then, once it is running successfully, to roll it out to the remainder of the plant. This approach has the benefit of reducing risk to the entire manufacturing facility, should any unforeseen problems arise.

However, with a phased approach, one must be careful to take into account the impact and compatibility with future modules and functionality. The phased approach is probably best in an existing plant where consideration must be given to current operations in terms of resource availability and impact on production.

On the other hand, a “big bang” approach can provide all the benefits in a single “go live.” While this approach will take more time and resources before any benefits from MES can be realized, it may be suitable for a new green-field site, where “impacts to current manufacturing processes” would not exist.

User Training

Finally, user training is one critical aspect of a successful MES implementation that is often overlooked. Not only must users be trained in the technical aspects of the system, they must also be made fully aware of the implications of any of their actions. For example, signing for batch records, in accordance with 21 CFR Part 11, takes on added importance in a non-paper environment [3].

Although training may seem a trivial task, scheduling it so that all operators are fully trained before the MES system “goes live” in a working plant requires careful planning. And it is every bit as vital to a successful MES rollout as the technical aspects of the particular system being installed.

References

1. ISA-95 Standard Enterprise - Control System Integration.

2. ISA-99 Manufacturing and Control Systems Security.

3. Title 21 Code of Federal Regulations (21 CFR Part 11) Electronic Records, Signatures

About the Author

Paul Murray is the IT/MES Team Leader for ProsCon, Ltd., a process control engineering company based in Cork, Ireland. ProsCon offers a range of services to customers in the drug, chemical and other industries, from process design to validation and modular design and build. Mr. Murray has more than 10 years of experience implementing automation, LIMS and MES within the pharmaceutical industry. He holds a Ph.D. in Physics from the University of Liverpool, U.K.