The Real Legacy of Legacy ERP

There Are No More Superficial Solutions

Background

Legacy systems are older computer systems, typically based around mainframe and mini-computer architecture. They describe the hardware, software and processes that deliver business services. They can be anywhere from 15 to 40 years old, and some even as “young” as 7 or 10 depending on the procurement decisions made at their time of purchase. Most of their work was originally designed for transaction processing and often did not readily communicate with other systems.

Essential Points

There are many problems with legacy systems. Legacy applications have their own legacy data structures and stores, with their own designs (architectures) that are implemented using a variety of technologies. This means that linking into or integrating them with or via other applications may be hard, or even impossible.

The lack of access to critical data that this entails prevents improvements that would allow more accurate reporting and forecasting in a business regardless of what new technologies are applied to the challenge.

The underlying functions of the business can at times only change with great difficulty, as they must work around the constraints of the processes enabled by the legacy system. In some cases where the business functionality must change, data from one system must be re-keyed into another system by hand which is a monumental task that can take years.

This activity wastes significant person-hours on tasks that should be automated. It introduces more errors into the organisation, and causes resentment in staff that are required to do the re-keying. These difficulties are still encountered on a daily basis.

In many operational ERP packages today, the real work (or the engine) is still enabled by a body of old and dated software, using business rules written long ago, in ancient software languages. These legacy jewels have been coddled and insulated from decades of technology change by sandwiching them between layers of newer software.

Old software born on obsolete operating systems can be literally tricked into running on a modern operating system by inserting a layer of new code beneath it. And it can be concealed from the outside world by wrapping it in layers of modern graphical user interface and Enterprise Application Integration (EAI) code.

In 2024, software written during the 1970’s, 1980’s, 1990’s and 2000’s still resides at the heart of many corporate systems. Its designers certainly didn’t know about newer development languages, powerful hardware, and all the other technologies and standards that exist today.

Instead they understood procedural languages, and how to write programs with access to limited memory, and the impediments of slow modems and network transition speeds. They knew about dumb terminals and raised data centre floors.

The historical investment in business rules was huge and remains so and in many cases, that old code still seems to do the job.

Ironically, the move to internet browser interfaces in the early 2000’s was a God-send to some companies with aging business logic code. Saying you had a web browser interface sounded pretty progressive from a marketing standpoint. Confessing that your old code was wrapped in a “screen scraper” did not. But technically, the result was the same; a core of old software was given a more modern face.

That meant that all many companies did was essentially just “pretty-up” our legacy systems. The modern “legacy” of those past legacy system refresh efforts is that we do not have that luxury today.

My Take

The core architectures of many ERP systems were designed and written long ago, before the real-life business demands of the 21st Century were understood. Connectivity and EAI support have literally been afterthoughts. Such considerations have been applied carefully at the margins of the old core software.
But technology, industry standards, and best practices are constantly evolving. The software that implements the business rules must also change, just as the business changes. And the pace of that change is increasing, not slowing. In fact its accelerating.

ERP architectures of the past will continue to fight against change and remain a major hindrance to organisational agility. They stand in the way of the new world of nimble integration and ubiquitous connectivity presented by modern system architectures that are born on the cloud.

Over the next few years, as the inter-generational leadership torch is passed from Boomers onto Gen X and Z, enterprises looking to replace any legacy applications, or even choosing applications for the first time, must choose wisely.