Planning System Decommission

Planning System Decommission

Successful System Decommission

Decommissioning a legacy or redundant system is the ultimate in “enterprise spring cleaning”. A long list of potential benefits of eliminating a system includes: consolidating duplicate systems that deliver similar functionality, making space for new technology to focus on the future, reducing licensing and support costs, managing risks inherent in any old technology, and having fewer applications for users to learn.

Despite this, many firms stumble when executing… after all, cleaning out the basement is not exciting work, you just want it done and over with. The following are key points to consider for a successful system decommission without compromising stakeholder needs.

Awareness of Current Usage

The most frequent mistake is to rely on assumptions and outdated knowledge to understand how the legacy system is used. A miss in this area can result in major delays and unplanned costs. Wishful optimism cannot be the basis of decision-making; only facts can tell an accurate story.

Identify the scope of change for the decommission activity. What capabilities does the system support? To what extent are they used? How important are these capabilities to the business? Is there a replacement system (all or part)? Who are the impacted stakeholders? What are the milestone deliverable dates to be achieved?

Identify and interview users of the legacy system to avoid surprises. Identify the business activities that the legacy system is used for. Understand frequency and penetration across user groups. The longer an application has been around, the higher the probability it is being used for a function other than its original purpose. Discussing how a system is used is important but watching it happen and seeing the output is far more effective. Often how users say they work and what they actually do are very different.

The longer an application has been around, the higher the probability it is being used for a function other than its original purpose.

Are you concerned this will add “time” to your plan? Interviewing users can require just a few days effort. A smart approach is to interview a strategic cross section of impacted stakeholders. This a small investment to avoid costly revelations.

Evaluate the technology consumption when establishing current usage of a system. The systems are often old, complex and tightly integrated. It is imperative to chronicle all data dependencies, integration points or implications to downstream systems and processing. With this complete picture, an execution plan and true business case can be achieved.

Without this, we often see decommission attempts thwarted when a residual system capability is found supporting an elusive yet critical function. The result is Double Jeopardy! Either continue to pay for the legacy system for indefinite periods of time OR break with critical business function, potentially impacting advisor efficiency or client expectations.

Be Strategic Going Forward

Sometimes the replacement system is known or forced on you, other times you have an opportunity to determine “how” you move forward. Consider the bigger picture when determining target solutions.

Find home of best fit for the capabilities of the legacy system. Don’t necessarily replace like-for-like. Consider whether existing systems or parallel projects are able to deliver on the majority of needs. Analyze the impact of building, buying or renting tools. Choose an application that can grow with you. Select a vendor that you trust – not only to meet your needs but maybe even to influence you along a better path.

Historical data can be extremely important. Data in a legacy system must be understood and rationalized to determine if data migration or extraction is necessary. If legacy data is important enough to maintain, having insightful partners to migrate data in a usable format can be important. The effort to plan is marginal, but losing credible legacy data can be a major blunder.

Build a roadmap to document and communicate the path going forward. Complex or evolutionary change won’t happen in one effort. It is important to share any incremental change (sequence, benefits, etc.) with stakeholders in order to obtain buy-in.

Take Action

Companies should avoid waiting until the last minute to plan a decommission as it could increase risk, cost more and it rarely ends up with the best solution.

Be realistic and proactive about replacing legacy systems.

Be realistic and proactive about replacing legacy systems. This is particularly important where completion milestones include vendor contracts expiring or deadlines for penalty fees.

Pull off the band-aid! You may notice that users continue to reference the legacy system, even after a new solution has been provided. This could signify shortcomings in the new system. It might also identify the need for training or for an improved communication plan. Users don’t like change and will continue to use a system where it is easier for them.

If you are confident that the business needs are met outside of the legacy system, pull the plug! Now, you can start saving, and avoid a potential usage conflicts.


Be sure to consider these insights to responsibly plan for a decommission, to achieve the business value as expected. Nobody likes surprises!

About the Croesus Business Architecture Team

Contact us to explore how the Croesus Business Architecture team can support your objectives with a well-conceived analysis for rationalizing the applications in your portfolio and to plan decommissioning of legacy applications with success and predictability.


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