By Russ Novak, ARC Insights
As the business processes of utilities evolve, stakeholders require substation control and data acquisition (SCADA) to support a growing number of higher-level applications. The demands on system functionality increase dramatically and the criticality of SCADA increases. Often the net result is the acceleration of SCADA system obsolescence and an earlier end of useful life for legacy systems. To remain competitive, companies must find a way to convert outdated system components to a state that allows them to support and enable the new business workflows. This is the principal factor driving initiatives such as SCADA migration planning.
A Short Analysis
The boundaries that define the extent of SCADA migration planning must include the entire complex interface between the automation and IT worlds. There are therefore a number of perspectives and issues to evaluate. Software is continually being developed to reflect the changing demands of business processes and workflows. Utilities must employ a SCADA system that provides a flow of data and information to support these ever-changing workflows of corporate business systems.
Within the SCADA system, components exhibit different endpoints of useful life. Hardware components of both IT infrastructure and automation generally have longer lifecycles than components of operating systems or specific software applications. Many utility or process companies succeed in extending the life of hardware components with best practices and asset-management programs. Predicting when a system will need to be replaced or when an individual component will fail is difficult. A proposal to upgrade a SCADA system based on the return-on-investment (ROI) of a theoretical change in business processes is often obtuse at best.
Other rationale for replacement or upgrading is more obvious and straightforward. An example would be excessive maintenance costs or lack of spare parts and support from suppliers attributable to cessation of a product offering.
The level to which migration planning must be developed and the degree to which plans are executed vary greatly among operating companies. Management’s operating philosophy and tendencies to adopt new technologies or business processes has an impact on migration planning.
Successful migration-planning programs must have early and continual executive management support.
Because utilities face difficult issues when considering SCADA migration planning, many utilities do not have a plan prepared, do not have migration plans on active status, have a roadmap but no definitive management approval or have a plan but no available funding.
SCADA Migration Planning’s Importance
For companies that employ a SCADA system for core operational support, the flow of data and information to support the continually evolving workflows of corporate business systems places a challenging set of demands on legacy SCADA systems. Software is continually being developed to reflect the additional demands of business processes and workflows.
Migration planning for SCADA systems must therefore include not only traditional and present requirements for levels of information exchange and control, but also the forecasting of the future demands on SCADA data and information flow for the enterprise or IT side of the business.
Replacement or upgrade decisions for SCADA systems are not just the domain of operations or engineering groups. Regulatory initiatives and the increasing complexity of the utility business require that the needs of all stakeholders both internal and external to the operating company also be met. Decisions regarding selections of new SCADA systems or components often include significant input from the IT staffs of operating companies.
The objective is to select a system, component or application with attributes that will allow a cost-effective upgrade or an efficient means of integration with legacy components.
Management’s operating philosophy has a strong bearing on how proactive the company is toward the development and establishment of an asset-migration plan. Successful migration planning must have an executive management “buy-in” at the onset of the program because typically funds must be expended over a multiyear period. Migration cannot be effective on an intermittent, start-stop basis or random intervals of approved expenditure. The degree to which an owner will commit–the amount of effort and expense expended to extend the life of a SCADA system (software and hardware assets)–will affect the profitability of an enterprise over time.
The level of in-house expertise and availability of personnel to develop migration planning also varies among utility companies. While larger firms may have sufficient in-house capabilities, the issue is the internal competition for those skill sets and the awareness of management for the need for migration planning. Comprehensive risk assessment analysis is particularly challenging. Smaller firms including local utilities might need outside assistance to draw up a first migration plan.
End of Life for SCADA Systems
When evaluating the lifecycle of a complete SCADA system, it is important to note that the components that comprise a SCADA system have distinctly different lifecycle lengths. While some owner-operator firms have inactive-use remote terminal units (RTUs) that are 25 years old or older, it is doubtful that a host or business IT system would be considered viable for that extended time. For SCADA, the end-of-life cycle occurs for reasons including:
- Hardware supplier no longer supports product,
- Maintenance costs escalate to an unacceptable level,
- No spare parts available,
- Underlying technology becomes obsolete,
- Original functionality is no longer sufficient,
- Hardware wears out, and
- Incompatibility between legacy equipment and newly installed systems.
Predicting when a system must be replaced or an individual component will fail is difficult. For hardware, service life expectancy is primarily a function of electronic component obsolescence, service environment and initial quality of product.
Designers and engineers must use care when selecting original SCADA hardware. Quality is important and the total cost of ownership (TCO) is more important than initial or installed costs.
Anyone maintaining components should keep up to date with supplier-recommended changes and updates. Should a supplier eventually withdraw product support, the magnitude of the impact on the system will be minimized and the timing will be less critical.
Personnel should provide a protective environment for RTU components. RTU hardware can have a long, useful life if carefully maintained.
It is important for personnel to obtain management approval early to sustain a viable SCADA migration plan. Plans usually occur over a multiyear span, and continual funding and management support are critical for success.
Personnel should factor in the operational and tactical issues when drawing up a SCADA migration plan. They should also consider the longer-range strategic business or enterprise changes that will affect the composition and functionality of the SCADA system.
It is important to keep SCADA migration planning dynamic; enabling additions to revisions and refinements or modifications to earlier assumptions and basis on which the plan was originally projected; as well as allowing forecasts to be used in generating milestone or objectives.
Novak is a research director with Arc Insights, specializing in systems integration, energy solutions and SCADA. He may be reached at firstname.lastname@example.org.