System migration: make sure you improve control, not just replicate

Paul Boughton
Ian Heathcock looks at the market drivers that are forcing businesses to confront system migration as a reality; what companies need to consider before making the leap and highlights some of the key principles to ensuring a smooth control system migration

Every company or business is different as they face individual challenges and issues on a day-to-day basis. But there are a number of key, yet common, business drivers that can impact on a business as it confronts an increasingly competitive landscape. Though disparate in nature, these drivers can be assessed separately or collectively as influencing the types of decisions that companies are required to make - and this is certainly true when it comes to focussing management minds upon potential process control system migration for the UK's manufacturing and production businesses.

So what are the types of market driver that will force any examination of potential system migration? They are varied, but will include among them:

Increased operational efficiency. You may have an existing plant that runs effectively, but you are sure that more can be achieved. The legacy system you have to contend with is not operator friendly, or has occasional failures, or can't be upgraded through lack of current technical knowledge. What should you do?

Reducing time to market. Your existing system may not possess the degree of flexibility you require in an ever-changing business landscape. Whether it is the desire to bring a new product to market quickly (a wish your current system cannot support rapidly), or an inability to cope with changing product strategies when the legacy system hampers potential competitive advantage within an ever faster product lifecycle environment. How can you change this situation?

Increased security. Your company may seek increased security around the control system. PCs are now less secure than ever, and the Windows 98/NT platforms are vulnerable to attack. Does this keep you awake at night?

Increased reliability and availability. It goes without saying that downtime and plant failures do happen, but how can they be minimised? It you are plagued with maintenance issues because your legacy system cannot be supported any longer with spare parts or easily available technical knowledge, then this will inevitably become an increasingly practical and expensive issue that will require your attention.

Increase product quality. The product quality issue is one many manufacturers must address.

In a batch process environment such as in the pharmaceutical industry, it is not always the production downtime that is the most significant issue, but is more likely to be the ability to consistently manufacture products to a required quality threshold to adhere to legislative commitments.

Any process-driven business will be grappling with some, if not all, of the above market drivers to try and maintain a competitive edge. But to achieve a true resolution, you must first assess the current situation and ask yourself some searching questions, particularly around the crucial area of your plant performance which could be endangered for some of the following reasons.

For instance, what will you unearth if you ask yourself the following:

- Is there an increased risk of system failure which could result in an expensive loss of production at my plant?

- Is my current DCS now obsolete?

- Does the current technical support meet our requirements as they stand today (not what they were five years ago!)?

- Am I finding it increasingly hard to secure spare parts and if I do manage to get them, am I 'surprised' at their cost?

- What about the financial stability of our system vendor and is their long-term future in any sort of doubt?

- Does the functionality of our legacy system meet our current and future needs?

- Are we hampered by the inflexibility of our system that means it cannot be connected with our corporate business systems - ie, MES/ERP integration is either impossible or extremely expensive?

- Are we experiencing a reduction in the knowledge available about our legacy DCS system year-on-year?

If you have asked yourself these questions, the answers may make it clear that control system migration is the obvious answer. But before you press ahead, there are also a number of other factors to carefully consider and weigh up:

- How will any new process control system guarantee an improvement in existing longer or unscheduled plant downtimes?

- Are you comfortable that the existing engineering functionality of the legacy system, optimised over many years, will be lost?

- Have you considered the investment associated with the engineering and field wiring and how much of it can you retain?

- What about your people? How can you assist them change over to a new system quickly and seamlessly?

- Do you have access to all the potential new functions after system migration? Finally, it will be a significant financial investment - will it pay off?

A lot to consider. But, certainly an essential analysis which will unearth the true benefit that system migration can provide for your business.

However, it is important to remember that system migration also offers flexibility in choice to hopefully match your individual needs.

System migration has many different approaches, ranging from the unsophisticated 'rip 'n' replace' everything stance, to the more information-led tiered approaches that can support manageable migration that may suit you better.

For example, these approaches can vary from replacement at HMI level with a modern operator station replacing the legacy HMI solution while the controllers and field level stay untouched, to extending it into plant extension with a new system and common operating and monitoring level.

You could even replace the legacy controllers with a new system while keeping the I/O interface level of the existing system. All can be possible and the approaches are designed with flexibility, practicality, risk reduction and cost considerations in mind.

The process of investigating the background and potential of process control system migration success is, in my opinion, founded on three guiding principles that must underpin any company's decision-making in this crucial area.

Migration does not happen overnight. Do not leave your decisions until a plant is brought to its knees. Make pre-emptive thinking central to your business analysis, and always remember that while the physical deployment of a new control system can take a matter of weeks, it is really the preparatory assessment, questioning and decision-making elements that are the most important part when considering migration.

Work with a company that will approach the problem holistically. Seek solutions from companies that can demonstrate understanding of the issues you face and can bring to the table an appreciation that they can pin point the problems you have.

Ensure they can then match their words and promises with thought through solutions, as well as technical expertise and manpower that means they go beyond the obvious and tackle the underlying critical system issues you face.

Their solutions should look to improve your business, not simply seek to replicate what was in place previously.

Get it right at the beginning and you are on the road to a smooth and successful process control system migration process.

Time spent highlighting the fundamental issues your business faces and then exploring the myriad of potential solutions will be time wisely invested. It will ensure the solution you select not only meets your needs, but also exceeds your expectations.

Ian Heathcock is Business Development Manager, Process Control Systems at Siemens Industrial Automation. For more information, visit

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