Constraint Management & IT - 20 Technical debt and legacy systems


Technical debt and legacy system


Technical debt and legacy systems are topics with profound implications for information technology and constraint management:

  • Technical debt is the price paid in the future for something done today, such as making a quick fix that generates errors in production, or something not done today, such as thoroughly testing a new feature
  • Legacy systems are mature enough to be running in production yet often old enough to embody previous generations of technology


Technical debt tends to be cumulative, and it accumulates most in legacy systems. So, what's this got to do with constraint management for IT?

  • IT implements business rules, but once those rules are automated, the rationale can easily be lost in the mists of time. Legacy systems then become a mix of rules that sustain competitive advantage and those that don't.
  • Legacy systems survive when they are mission-critical, but over time they become increasingly difficult and expensive to maintain. And IT workers may not see them as a viable career path.
  • Legacy systems often dominate the IT portfolio budget. Mandatory systems which generate no revenue compete for attention with new projects that could generate revenue.
  • Legacy systems modernization or replacement are fertile ground for mega-failure projects. Extracting business rules from legacy code and reimplementing them on modern technology requires courage.


More applications of constraint management for IT are covered in "Exceeding the Goal."




To enhance your expertise, Marris Consulting organizes training sessions on Theory Of Constraints applied to production and projects environments



Marris Consulting, expert in Theory of Constraints & Critical Chain Project Management


Marris Consulting is an expert in the Theory of Constraints (ToC) and Critical Chain Project Management (CCPM). As industry consultants, we are focused on helping process and manufacturing industries reach their highest levels of performance by using Constraints Management  combined with Lean and Six Sigma. We also use Critical Chain Project Management which we sometimes combine with Lean engineering to improve project performance. If you are unsure about the actions which need to be implemented to improve operational efficiency, our industrial management consultants can also conduct a performance audit. Furthermore, our experts host numerous Theory of Constraints (ToC), lean and project management training sessions throughout the year.

About Marris Consulting

Marris Consulting is an industry consulting and training company specialized in the Theory of Constraints (ToC) and Critical Chain Project Management. We focus on improving the performance of manufacturing and process industries by using Constraints Management combined with Lean and Six Sigma. To boost project performance, we also use Critical Chain Project Management (CCPM), which we sometimes combine with Lean Engineering. Our 2-day performance audits, our performance consulting services and our project management, Lean, ToC & CCPM training by our industry consultants offer a wide range of solutions to help our clients around the world reach the highest possible levels of performance.

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