Making a business case for legacy systems

Making a business case for legacy systems

Before we invest, we make a business case. We put costs versus benefits, project it over time and when the value exceeds the costs in a relatively short period, we give the green light.

Building software is investing. And old operational software is a real money maker. The initial investment is years behind us. We are reaping the value this machine produces. As software developers, we hope the systems we build will last for the ages.

When the glamour of Building Something New is over, eyes move to The Next Big Thing and nobody pays attention to the value machine.

Over time, it gets harder and harder to get a budget for maintenance, because the money goes where the eyeballs are.

When after years of flawless operation, the machine starts to sputter, it’s never a dramatic stop. The machine usually doesn’t grind to a screeching halt. Small changes get expensive and fraught with error. Hardware gets antiquated and dependencies reach EOL. Slowly but steadily the rot sets in.

Paradoxically, the screeching halt would be easier. If that 10-year old user management system refused to reboot and nobody could log in, we would throw money at it to stop the fire.

Legacy systems are not unloved. They are not forgotten. They are just taken for granted.

In a corporate environment where there is a myriad of fires to fight, it’s hard to draw attention to that sputtering machine in the corner.

Yet it’s vital we do. And the best way to do this is to make a business case for renovation.

  • How long are we planning to keep the system operational? 1 year? 5? As long as possible?
  • How many active users do we have?
  • How many changes did we develop in the last year? None, it’s stable? Thirteen tickets, so it’s pretty volatile?
  • What would the impact of an outage be? Would it affect mission-critical processes?

Based on these kinds of questions, we can make a profile of the system.

If the system is used by 25 people, never changes and isn’t vital, there is no business case for a big renovation.

But more often than not, we’ll find a system that is used intensively, has trouble keeping up with the necessary adaptations and would be disruptive if down.

All of a sudden, throwing a few thousand euros at it becomes a no-brainer.