On many plants it is common to use a manual approach for managing changes to automation software (PLC, CNC, robot, agv, etc.), perhaps even tracing them on Excel sheets.

The change is made and the technician or engineer saves the new software program in a directory appropriate on the department server. It works, True? Yes, as long as you do it regularly.

E if that person forgets to do so or postpone it until later and then it doesn't get done? We are human after all.

What happens if unintentional changes are made and the new program does not work?

If you don't have an older version, do you have to rewrite it completely?

What happen if the device (PC, Server, PLC etc.) is hacked and the program is modified without your knowledge?

these are just a few scenarios where a manual approach (or even an open source versioning product) they can't help you.

First of all, let's define what a Change Management System (CMS) is or automation software change management system. A CMS of this type it is a centralized system that manages changes to the logic of software programs and control devices such as PLC, CNC, HMI, PCbased control systems, robots, drives and factory automation programs in general.

ServiTecno's proposal for Change Management in an operational environment

MDT Autosave

At least, a CMS should have the following features:

  • An archive of previous revisions of programs
  • The ability to detect changes
  • Tools to document changes and make them visible to users
  • A historical record of who made the change, when and from where it was made
  • Secure and controlled access for users and workstations

A good CMS

Furthermore:

  1. Get and save updates automatically of the program on the server as they are modified.
  2. Control Editor operations associated with user permissions.
  3. Provides change management for remote and non-networked devices.
  4. It supports a variety of devices and any PC-based application.
  5. Provides a way to track activity linked to the changes through an online portal.

Always remember that the automation level of any plant is at risk of human error, equipment failure, sabotage, power surges/outages, and fires.

So how can a CMS protect us from risks?

  • Human errors: If someone makes changes to a program that causes unwanted actions or performance, or corrupts the program due to unintended changes, the previous version of the program is readily available.
  • Equipment failure: let's remember that the equipment can also break (and often does). If the hardware failed and the only valid copy of the program logic was in that hardware, the plant has a problem. With a CMS, the hardware is replaced and maintenance personnel download the latest version of the program to the processor, with only a few minutes of downtime.
  • SabotageAs unpleasant as this threat is, someone could directly connect to many devices (especially those in remote, unsecured locations) and modify the software with harmful results. A CMS is designed to store processor passwords (for some processors) so they are not accessible without going through the CMS. In addition, the CMS will periodically load logic from the processor for comparison against the copy-to-file version. Changes can be identified graphically and immediate notification sent to responsible persons, usually via email.
  • Power surges/outages: Power problems can cause the equipment to lock up or disable. If these situations cause a loss of the program, it can be reloaded by the CMS after a hardware reset.
  • Fire Protection: any fire is usually a serious event. If a single device or an entire department is lost, storing all software logic in an organized and central CMS repository speeds up time and reduces costs associated with resuming production. (NB: some insurers are starting to consider the use of a configuration management system in risk profile assessment for policy cost reduction.)

Without adequate safeguards, these events can lead to downtime, reduction of product quantity and quality and even security/safety issues.

While a manual backup approach may seem adequate and sufficient at first glance, experience has shown that plant personnel have a lot of other tasks to attend to and little time to always manually back up programs on a periodic basis. In addition, increased visibility into the changes made allows for potential process improvement in production and effective use of a CMS application, can quickly pay for itself the investment made in the CMS.

There are many real examples of systems that have benefited from the use of a CMS (such as Autosave by MDT, distributed and supported in Italy by ServiTecno for change management, version control/backup, configuration management and PLC software , HMI, PC in production, robots, CNC/DNC etc…

Here some Application Stories

On many plants, the decision was made to implement a CMS after experiencing downtime and product loss.

A CMS is necessary to safeguard automation systems from risk events, but it can also bring benefits for compliance with standards or regulatory requirements and more, certainly with an improvement and traceability of maintenance processes.

You can find the white paper here: “Safeguarding Your Plant Automation Systems with Change Management” for more information on the capabilities of a CMS

https://www.mdt-software.com/plant-automation-best-practice-white-paper/

And more CMS case studies, application stories, and an ROI calculator can be found here.

https://www.mdt-software.com/tools-resources/