Using examples from instrumentation and control engineering, Dave Gibson of Aveva takes a closer look at how the efforts to deliver plant asset optimization can be frustrated, and how a simple desktop calculator can help to focus management attention on a potential solution.

Dave Gibson, Aveva, UK

Instrumentation and control systems play a vital role in all aspects of modern living, from helping us drive our cars, to safely running large power facilities and petrochemical complexes.

According to recent industry research, instrumentation is the biggest spend item in any plant. Capital expenditure on buying new instruments in 2010 was estimated at $5bn, with maintenance and operation costs reaching $4.9bn. An estimated 70 per cent of plant data involves instrumentation items in some way. Whichever way you look at it, instrumentation is a significant part of the retrofit projects that are the basis of effective optimization.

Much of the technology that currently supports the instrumentation and control disciplines is addressed squarely at the plant design stage, but this is only one piece of a much bigger story. There is an equally important role for this technology in enabling existing plants to optimize the instrumentation and control systems already in place, through extension and retrofit upgrade. As one seasoned instrumentation engineer recently told me: “It’s about squeezing a little bit more out of the system, and adding value to legacy data by taking it to the next level – that’s what optimization really means.”

Instrumentation and control: the industry reality

It has to be said that much of the cost associated with instrumentation and control is probably unnecessary, regardless of whether we are talking about new build or optimization projects. It arises because the technology used to plan and design instrumentation and control systems has often been developed with little regard for how engineers and designers actually work.

Procedures that can be perfectly straightforward if represented graphically – rerouting and reconnecting wiring, for example, or segregating cables – are, traditionally, all too often dependent on manual, tabular data input, which is time-consuming, expensive, and prone to error. This is most certainly not a recipe for effective asset optimization. In fact, in late 2010 Aveva spoke to instrumentation and control experts from across the industry – engineering design and operations, power, oil and gas and other process plant sectors – and identified a number of key areas where many instrumentation design technologies fail to effectively meet the requirements of both engineering design and in-plant engineering (operations) users.

A separate white paper1 has been written on the subject of these ‘headaches’, faced daily by instrumentation and control engineers, in their efforts both to design new systems and optimize existing ones. We will draw on some elements of the paper here.

Optimization: The challenges

Imagine a well-established plant, with high levels of operational demand. It has a pressing need to revamp and extend, but as part of this process it also needs to optimize much of the infrastructure that is already there.

This inevitably places high expectations on the design technologies that are in use. Here are just a few examples of the challenges that asset optimization poses, and the effects that they can have on efficiency and throughput. Some are applicable across all disciplines, and some are necessarily more focused on instrumentation and control, but both types of example serve to illustrate the point.

More demanding ‘Management of Change’ requirements

Optimization often requires retrofit activity, and this brings with it a growing need to thoroughly track and manage change, whatever the discipline. Let us look at a specific example. In instrumentation and control, it is becoming ever more critical to manage cabling during retrofit changes, in order to identify cable that can be re-used.

This is an engineering imperative, to be sure, but it is also an economic one. The price of copper – the key component in the cabling that forms the basis of any instrumentation and control system – is at an all-time high, in a discipline that already ranks among the most costly of all design processes. The most effective method of re-use is to reconnect existing cable to a new instrument; so, for example, a field instrument might be connected to a new component within an existing field box to achieve a more optimized control philosophy.

There must be a full accompanying revision history, but the need is even more contextual than that; it is for consistent data that is relevant at the right time. For the discipline engineer who is actually carrying out the instrumentation and control optimization activity, this means full wiring connectivity information and complete instrument data.

Nowhere is this more apparent than in the realm of safety. There have recently been significant changes to legislation, partly as a result of past accidents. Standards such as ANSI/ ISA-S84 and IEC 61508/61511 demand that a full understanding of certain system elements is now critical for safety management.

For example, there is now a requirement to identify safety-critical loops (such as emergency shut down/ESD) as part of safety instrumented systems (SIS) measures. These loops need special preventative maintenance measures, but they also need to be clearly identified for process hazard assessments (PHAs), and in order to undergo safety integrity level (SIL) analysis and evaluation. Designer and engineer therefore both need to be in possession of the right information, in the right place, at the right time. They must understand not only what changes are necessary and where they have occurred, but what their impact is likely to be.

Documentation update

It follows that any changes to the facility design and its operational conditions require corresponding changes to the documentation. Optimization work can typically affect items as diverse as alarm points, set points, calibration, instrument settings and wiring.

The Aveva instrumentation business value calculator

The impacts of these changes mean documentation and process safety information (PSI) that accompany these items need to be rapidly trackable and auditable. Indeed, the reliability and currency of these information sources is increasingly strictly enforced by regulatory agencies, and heavy fines can be imposed against non-compliant businesses.

Systems integration issues

The redesign that is an intrinsic part of retrofit and optimization can suffer enormously from a lack of integration between information systems. Design decisions made in one piece of software or one database often have to be manually replicated in all associated applications.

It is a massive drain on resources, whatever the design discipline involved. Wiring design, for example, is a multi-phase process, involving loop diagrams, schedules and terminations, yet many of the design technologies currently in use are unable to integrate these activities and the data on which they are built into one application. The wiring designer has to co-ordinate design data manually between several applications. This is an open invitation to error, as well as a seriously inefficient use of a technically skilled individual’s time.

To make things worse, input of data into many of these design applications is often via table and spreadsheet. These provide no means of visualizing relationships and using those visualizations as the logical starting point for the creation and editing of the design. Another layer of pointless complexity is often added by the need to request an output plot from a designer, which can take many hours of work. Optimization, at least on the instrumentation and control level, is deeply compromised if all deliverables, e.g. loop diagrams, schedules and terminations, cannot be created and edited from the same visual engineering environment.

Lack of visual context

Retrofit optimization can be greatly hindered if there is no effective integration of the retrofit data with any physical representation of the existing condition. In any engineering discipline, this makes it difficult for engineers and designers to make judgements on detailed design issues like spacing, tolerances, buffer zones, clashes, and so forth, but also on procurement and materials issues like quantities and volumes.

Cable routing is a good example from the instrumentation and control world. Cables come in many different types and need to be routed to effectively segregate them by voltage, function, flux, heat dissipation, and so forth, while economizing on the cable length. This combined requirement is virtually impossible to meet if the user cannot visualize a detailed representation of the condition at hand, and view it to plan his strategy for executing the change.

Granted, sending out an operative to run a physical measurement in the field, so that some sort of limited visual representation of the environment can be attempted, is an option, but it is a time-consuming, expensive, and often hazardous one.

Advanced integration with a pre-existing model, on the other hand, can offer possibilities like automated cable measurement, and in this scenario routing and segregation can be generated instantaneously. This results in greater control, less rework, enhanced safety and compliance, without risky and time-consuming guesswork. The bottom line can be millions of dollars in savings for optimization retrofit, and material procurement.

Data and document guesswork

Retrofit and optimization activities, like any engineering project, generate a huge amount of related information including data sheets, documents, and so on. I wrote earlier about the importance of recording and tracking change to this documentation, and it goes without saying that the documents need to be accurate. They also need to be complete – not only within themselves, but also in the way they are linked to other related data and documents. Many systems completely fail to link this information together, as it typically comes from both internal and external sources. Engineers and designers involved in retrofit activities therefore have to ‘second guess’ both the nature of the information and its location.

Apart from being terrifically time-consuming – recent studies indicate that the search for information can take up as much as 60 per cent of an engineer’s time – this also perpetuates the problem of ‘unknown unknowns’. Clearly, an inability to understand the current environment is not a good foundation for making decisions about how to create an optimized one.

Disruption is an inevitable by-product of this limitation, as a designer or engineer will tend to approach a colleague to help find information, thus wasting two people’s time instead of one! The majority of safety-related incidents have also ultimately been related to poor information accessibility, so the need to diminish this risk substantially is a high priority.

Technological stagnation

Technology vendors’ inability to get to grips with some of these optimization challenges has undoubtedly exacerbated them. This is true across all disciplines, to some extent, but it is particularly noticeable in instrumentation and control. Some design technologies in widespread use in this market have not undergone any significant development for ten years or more.

Others simply no longer exist, because the vendors are out of business. This means that the technologies in question are incapable of evolution, and that they are no longer supported. If the wheels fall off the technology, there is simply no one there to replace them. Instrumentation networks are therefore often the principal source of potential failure in any optimization design process!

A way forward?

Words are cheap, as the saying goes, but numbers have an extraordinary ability to focus the mind. Elements of the challenges to optimization are evident from what we have said above, but where is the numerical justification? Where is the arithmetic proof that will convince those responsible for the commercial viability of the asset that the effectiveness of the optimization effort can be either compromised or enhanced by the way instrumentation and control retrofit is handled?

Aveva came up against this question so many times that we decided the only way to answer it was to use real customer data to make a direct comparison between the traditional approach to instrumentation design, as described above, and the integrated, graphical visual engineering approach that Aveva has adopted.

We gathered the data in from a number of international customer and prospect feedback groups and the results were as we expected. Much of the expense associated with instrumentation and control activity, across both new build and optimization products, is simply unnecessary, because it is caused by inefficiencies and integration issues in the design technologies.

Articulating this message was, in itself, a challenge, so we developed a small desktop application – the Instrumentation Business Value Calculator (BVC), to paint a more interactive picture of the efficiencies that are at stake.

There is more detail on the BVC above, but for the moment there is a clear conclusion to be drawn. Can we, to return to the title of this piece, actually calculate the value of asset optimization? Well, as far as instrumentation and control are concerned, we already have.

ABOUT THE AUTHOR

Dave Gibson is head of product strategy for electrical & instrumentation systems at Aveva.

Footnote

1. The Aveva instrumentation whitepaper, Top Ten Instrumentation Headaches, can be downloaded from www.aveva.com/whitepaper

The Instrumentation Business Value Calculator

The shortcomings of the design technology often used in instrumentation and control projects, both new build and retrofit, spurred Aveva to build a simple desktop application to calculate the impact of hours of designing and managing instrumentation and control systems, using technology that is not inherently geared to optimization. This tool is called the Aveva Instrumentation Business Value Calculator, or BVC.

The BVC’s logic is based on feedback from industry experts involved in Aveva’s customer research. It constructs a comparison, between conventional technologies and Aveva’s own visual engineering-based solution, Aveva Instrumentation, of the resources required to deliver the benefits that are key to the success of any instrumentation and control work. There is no distinction between new build and as-built contexts; the logic is applicable to both situations.

The BVC works by enabling users to input actual values about their instrumentation and control project, such as head count, hourly costs and input/outputs. On the basis of this data, the BVC then calculates savings, in man hours and cost, across a number of typical project deliverables including: loop diagrams, hookup diagrams, datasheets, block wiring diagrams, junction box diagrams, cable route layout diagrams, etc.

Instrumentation specialist Dave Gibson said the BVC reflects real-world evidence from users of Aveva Instrumentation who have experienced “benefits such as a 30 per cent cost saving in man hours and a 50 per cent rise in productivity.”

A copy of the BVC can be requested at: www.aveva.com/instrumentation 

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