Thames Water: SCADA Upgrade Project

A single utility-wide information system

A current project which is being undertaken by Thames Water has shown that key functionality in its choice of Wonderware technology has resulted in a better development environment and subsequently a better operating environment, which is the subject of this paper.  The automation and information infrastructure in many utilities has in many cases reached or has exceeded its life cycle. Upgrading such systems is a far reaching matter that will inevitably be expensive and time consuming, compounded by the underpinning technology having moved on through several generations in the meantime. Utility operators are faced by a mountain of alternatives and the final choice will have significant impact on operability, customer satisfaction and regulatory compliance.

Situation

The accrued legacy, often through inadvertent ‘obsolescence drift' and the high rates of technological development, can leave large asset owning companies with major difficulties in support (parts and know how) and the inability to properly integrate plant into subsystems and a single utility-wide system. Pressure to reduce operating costs and increase customer satisfaction will seem to be impossible goals when challenges include dealing with technologies from the 1990's and before.

Selections

In making selections for suitable systems the first one to address is whether to develop a focussed bespoke system, to utilise a standard product, or to specify an underpinning standard technology. The business risks of bespoke systems are never offset by the apparent advantage of them being targeted at actual requirements as one is exposed to limited resource for support and further development with the risk that without adequate funding (which in this case will be project based). A bespoke solution will rapidly become legacy in its own right as changes and required by the natural evolution of any undertaking. The extreme opposite is to consider a system that has been designed as a generic utility solution, but somehow does not meet many of the known or as yet unknown requirements of a particular company.

The balanced third way is to utilise technology which has the appropriate functionality and structure to meet the operational requirements of a company, combined with ease of execution and the inherent reduction of business risk; or said in a simpler way, to specify something which is known to work, has self evident advantage and is supported by a large vendor.

Setting out the vision

It is not unreasonable to spend time in considering ‘what will success look like?', and its implications (and even assumptions) about functionality and the final operating experience. This can be modelled at a high level: such as, there is an alarm, can I interrogate the plant remotely and automatically raise a works order and dispatch an engineer with the correct skills and parts to the right location? Or it may be that whoever delivers a part of the project that the result should work in the same way and look identical to the whole - a pump being a pump regardless of the SCADA integration company!

Part of the vision may be expansibility, one often having to plan for an uncertain future (for example a future with water shortages and rising populations). Cost reduction may mean de-manning or zero headcount growth, so how can a system be structured to operate effectively with perhaps a single supervisor?

At this stage setting the vision high should be limited by imagination only, not by experience of legacy systems, which by definition are the problem.

 

Make it so!

Fulfilling the vision is helped by an understanding of the automation process, both in development and in operation. The latest automation technology has functionality which helps in both the acquisition and in ownership stages of the resulting scheme. The later is as important as the former as the utility company will not wish to feel that they have procured something which is unmanageable and not in tune with their continuous improvement programmes, which is also another argument for avoiding a bespoke system.

Spotting the functionality that will enable the vision

A large project will have many development engineers, working in different places and for different sub-suppliers, how is the utility company to make sure that standards are adhered to?

Wonderware technology is based upon Microsoft .net framework, by which one can create standard objects that can be thoroughly specified, thoroughly tested and distributed to all stakeholders. This will ensure that a pump is a pump (mentioned earlier) and looks and operates the same way wherever an iteration of that object is deployed. This applies to a whole host of other assets within a water utility's ownership, they can be symbolised by standard objects, with groups and nesting to provide a ‘gold standard' set of functional objects for use wherever and by whomever has the need. This technology automatically ensures that with some upfront effort that all subsequent work is not only to the same standards but also can be undertaken efficiently. This is a field proven advantage of Wonderware's System Platform using ArchestrA technology.

A very predictable characteristic of water utilities is large size, with control centres and many remote stations, a solution for utility-wide information will have to cope with being deployed over large areas; many component parts coming together to produce the complete solution. Thus the selected technology must be capable of being deployed in many places with significant distances between them. With Wonderware System Platform this is achieved through the aforesaid object orientation and also with the notion of a galaxy (or multiple galaxies), which effectively cluster operations into a single architecture. This is not expansibility (although that is needed for inevitable system evolution) but more the capability of the system to cope with the size of the application.

To avoid the risk of technological obsolescence drift it is important a solution utilises the latest beneficial techniques within IT structures; in this case virtualisation was used to provide future proof application portability and segregation.  More basic functionality such as device connectivity to the controller level is still as important as ever to allow the system to work with a variety of field control equipment such as PLC's.

Additionally, systems have to be capable of being made safe and protected through rigorous regulations such as those defined by CPNI (Centre for the Protection of National Infrastructure). This involves access security, firewalling and operational integrity.

Operational requirements

Enabling a single central control room for the entire scheme means that a single operational view is available, with consequences of operational decisions being visible immediately, without recourse to viewing other systems which may even be located at other locations. This centralised approach has to be augmented by portable devices which allow local visualisation and status information displays on demand, such as during a maintenance visit or in the rapid remedy of leaks.

Alarms from such a large system will occur and need careful handling so as to not overload central operator screens, with the resulting risk of a critical alarm being overlooked. Equally important is to provide the central supervisor with a way to raise a maintenance action as a result of an alarm. System integration with other systems, such as computerised maintenance management (CMM) should be investigated to allow smooth and seamless operational procedures to be executed.

This raises the issue of SOP's (Standard Operating Procedures) which may be in a master document that is referred to when a particular event occurs. Modern technology allows SOPs to be integrated into the core system, and, importantly, they become observable in real time on the system screens as a particular event is addressed (this includes monitoring manual operations, especially when portable devices are used in the field). The central supervisor is thus assisted in knowing not only that an event has occurred but exactly what is happening to remedy the situation, with the assurance that the remedy is according to agreed SOP's. Wonderware ArchestrA Workflow, a functional module within System Platform, provides this beneficial functionality.

SCADA displays using such technology handle multiple monitors and provide clear insight to the whole system, without intuitive displays using standard elements (provided by object orientation) the clarity of a situation and the subsequent operational decision making would at best be delayed and at worst erroneous. SCADA is the human interface to all the technology that has been previously mentioned.

Summary

Bringing decades of technology in water utility companies into the current day is not to be undertaken lightly, many decisions have to be taken and advice should be sought. The key issue is to define and set a vision of what a success will look like, set the vision high and then seek the technology that will enable this vision (as much as possible, and probably on a phased basis). Although certain aspects of the legacy system will have proven to be beneficial (and should be retained, or enhanced) it is a mistake to use the past as an overburdening guide to the future, simply because things that were impossible then are common practice now.

Needless to say it is key that the operational challenges within water companies are fully and comprehensively addressed by the proposed solution; but it is invariably the case that ‘indirect' benefits of new technology will appear during a project's role out, these are the icing on the cake and should be absorbed into the scheme or fully exploited at a later development stage.

For more information on Wonderware's approach to Water & Water Services please email info@wonderware.co.uk