There is no denying that plant floor automation can dramatically improve efficiency and increase productivity, but there is an unintended consequence of automation that can make it problematic. That consequence is the increased dependency on new technologies like PLCs, PC-based control systems, SCADA systems, and HMIs. As long as everything is working as it should, the automated workplace proceeds as a well-oiled machine, meeting every quota and price point. Of course, when something is not working as well as it should things can get complicated.
Imagine if a type of hardware used in your process has proven to be ineffective and you’ve decided to replace it with another model. Not only does the hardware change, but changes must be made to your overall control logic. This is likely to require changes to your PLCs, your SCADA system, and your HMIs. And what if the new equipment is even less efficient and you decide to roll back to the previous version? All of these control logic changes must be undone.
Change Management Systems
These concerns have become of such major importance that many companies are investing thousands of dollars and countless man-hours in software designed specifically to help manage plant-wide changes. These Change Management Systems are intended to reduce the overall cost of implementing plant-wide changes by automating as much of the process as possible. A good CMS will provide the following features:
– A backup/archive of prior revisions of programs change management tool
– Tools for documenting changes
– A historical record of what and when changes were made, and by whom
– User- or role-based permissions determining who is able to make changes
– Disaster recovery procedures to recover from hardware failures
– Notification of changes
These change management functions have been performed manually in most cases, requiring enormous investments of time. Furthermore, the updates made to PLCs and SCADA systems typically require taking the process down while changes are made. This inevitable downtime creates another enormous gap in profitability. Even when a sophisticated CMS is employed, there is no way to avoid the fact that traditional SCADA and HMI systems are inextricably linked to the hardware that they are monitoring. Any significant change will require taking the entire process down and starting it up again after the changes are fully implemented.
Is There an Alternative?
If it seems that change management is just a fancy new way for software developers to make more money on some unnecessary product designed to solve imaginary problems, just think about what would be involved in making plant-wide changes in your enterprise. Would you have to make changes to your SCADA system? How long would that take? Would you have to update your HMI screens? How many of them? And how long would you have to take the process down in order to make these changes? Consider the cost of the labor. Consider the lost production due to downtime. And imagine if the change you made does not produce the intended result, and you want to roll the process back to a previous state. How much more time and money would that cost?