Other stories: 2009’s winners and losers in the oil industry | 10 events in oil’s history that shook the world | Top 10 Gulf mega projects | Top 10 largest publicly traded oil companies | Top 10 National Oil Companies by production | World’s 10 largest oilfield services companies | World’s 10 largest oil and gas contractors
Expert Views: Each week www.ArabianOilandGas.com invites a leader in their field to explain the latest developments in a given sector. This week, John Schofield, life cycle management marketing leader, EMEA, Honeywell Process Solutions, presents his article: Reaping cost benefits for the long run: Advantages of life cycle management
What is the most cost effective way of looking after your Distributed Control System (DCS) for the next 10 years or more? Considering the current economic scenario, this question becomes even more significant.
If we look back to the 1970s, digital DCS experienced a tremendous level of success across the world – including in the Middle East. The value of the installed base of these systems today is US $65 billion. The main problem now is that these systems are ageing.
In other words, obsolescence is either already with you or is approaching – not just in terms of parts, but people as well. The availability (or non-availability) of parts is a tangible issue – however, people are also a valuable resource and many of the engineers who were experts on the older system are now approaching retirement. New engineers are conversant with the latest systems but struggle with the older systems. Moreover, they are not inclined to learn as there is no obvious future for these ageing systems.
The reliability of these early systems has been excellent but this factor has also depended on the atmospheric conditions, so different sites have different data. The question to ask now is whether the failure rate of boards on your site is starting to climb the end of the bath top curve, as a result of which you may be experiencing production losses, increasing safety risks, or facing environmental issues.
Perhaps you are already exploring the advantages of the latest systems which can improve throughput while reducing energy costs and maintenance costs. These systems enable the user to respond to market volatility and optimize production schedules while determining viable pricing structures. The new Human Machine Interface (HMI) improves operator effectiveness thereby reducing or avoiding incidents and enhancing productiveness.
So, what is the best course of action? There are three possible routes. The first is to refresh replacement boards with new electronic components, which are available from some manufacturers, thereby extending the lifespan of the old systems. The second option is to carry out an incremental migration – perhaps in phases – of the top layer of the system and changing the HMI. The third possibility is to make a wholesale change of the entire system, essentially a “rip & replace” strategy.
Each of these strategies has a ‘cost-and-benefit’ associated to it. The first option, which is an electronic refresh, will be low cost, very low project risk and will extend the system’s lifespan but will not add any new benefits. The second option, incremental migration, will incur medium cost, have low project risk and provide significant benefits with the new HMI. The “rip & replace” will be high cost, high project risk but will see significant benefits. When comparing the cost versus the advantages, we can safely assume that incremental migration produces 80% of the benefits at 10% of the “rip & replace” price.
So how does one proceed with such complex decisions? The best place to start is with an automation plan that includes an assessment of the parts availability, the reliability and the basic control performance. Then carry out an HMI migration which should preserve your intellectual property whilst giving you access to the wider world with OPC connections. New graphics should enhance operator effectiveness and should be designed for abnormal situation management with modern alarm management and built in automated procedures.
You would have now upgraded your systems, but, like everyone since the late 1990s, you have joined the world of open systems with the huge benefits of the rapid development of PCs and servers. The downside is the need to refresh these elements on a regular three to four year basis. This has been accepted in the office environment but only begrudgingly on the process plant where the previous lifespan was as long as 25 years. In the automation plan it will be necessary to build in a regular upgrade of the hardware and associated software for all the PC and server elements.
The final elements in the life cycle picture are the essential yearly support costs for maintenance of the hardware and software. To ensure hardware and software remain compatible, regular updates and upgrades of software should be part of the maintenance program.
Life Cycle Management (LCM) is the umbrella contract covering the costs and benefits of incremental migration, regular upgrades of PCs and servers, and full maintenance. LCM is designed to obtain the best out of your DCS now and into the future whilst spreading these costs evenly over the next 10 years.
