Preparing a Critical Infrastructure Utility for a High-Risk CIS Replacement

A mission-critical system at the center of customer operations

A large U.S. natural gas utility initiated the replacement of its aging homegrown mainframe Customer Information System, the platform underpinning billing, customer service, meter-to-cash processes, and regulatory reporting. For decades, the system had served as the operational backbone for millions of residential, commercial, and industrial customers.

Over time, the CIS became tightly coupled with more than 70 surrounding applications spanning outage management, meter data, payments, field operations, customer communications, analytics, and regulatory reporting. Many integrations were custom built, insufficiently documented, or dependent on manual workarounds accumulated over decades of incremental change.

Modernization was necessary to support evolving rate structures, distributed energy resources, digital engagement expectations, and long-term cost efficiency. However, the complexity of the environment introduced substantial execution risk. Any disruption could lead to billing inaccuracies, delayed revenue collection, customer dissatisfaction, or heightened regulatory scrutiny. The utility required a path to modernization that would allow replacement of a core system while preserving operational stability and public trust, and that could support future change as regulatory requirements, technologies, and customer expectations continue to evolve.