Mining the Corporate Data Domain Safely and Securely Across the Enterprise

Part 2: In-house Historical Data Tools

The Challenge

In the 1990s Entergy developed tools inhouse to pull different types of data out of the operational SCADA system, store it and/or share it to various departments. One in-house tool in particular has been used by hundreds of internal users for day-to-day equipment monitoring and viewing of historical data. A valuable feature of the in-house solution, however, was that it stored all of the data, all the time. Unlike solutions that require values to be selected and saved ahead of time, this system stored all the data so that it all could be examined anytime, after the fact.

Yet although the in-house developed tools were a popular success, they had limitations in terms of functionality and reliability. For example, there was no reasonable ability to systematically obtain and analyze the data programmatically outside the original user interface; the biggest reliability issue was a lack of data feed redundancy, which resulted in gaps in the data – a serious deficiency.

Looking for Answers

In 2003 Entergy made the decision to replace the in-house tools with an industrial quality application that would meet the desired functionality and reliability goals. Existing data historians were examined and found to be good general-purpose systems that require the user to re-define and remap their data into a new framework.

Given Entergy’s resource constraints and the frequency of database updates, the additional burden of remapping large data sets wasn’t deemed practical. Instead, a system that was tightly integrated with the existing SCADA system was needed to avoid undue maintenance and duplication of effort. The decision to build an Entergy system was simplified by the fact that all of the Entergy companies use a common EMS supplier.

The Solution

Not finding any suitable products in the marketplace, Entergy selected Nobadeer Software to develop a technical solution based on the desired functionality and the following set of real world objectives:

• Capture all of the data, all the time.
• Zero maintenance required.
• Keep unauthorized personnel out of the security perimeter.
• Provide programmatic access to the data store.
• Incorporate modern application development standards thereby providing stability, resiliency, and robustness in the platform.

After a rigorous round of design reviews and discussions of Entergy’s needs, coding was initiated in 2003. The resulting data storage and retrieval system – called Pegasus RDS™ – was put into service at the first of Entergy’s regional control centers in 2004, and was soon storing data at all four regional T&D centers and the central transmission operations center. Since then, the system has been expanded to include a number of reporting and data analysis tools.