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4.5.18: Scenario 17 – Refactoring Impact and Regression Instability

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    Scenario 17 – Refactoring Impact and Regression Instability

    Scenario Context

    Following the decision to address architectural inconsistencies, ZynoxDev initiated refactoring activities focused on the synchronization and data validation components.

    The intent was to:

    • Align the system with original architectural standards

    • Reduce long-term technical debt

    • Improve consistency across modules

    Refactoring has now been partially implemented.

    However, early results show unexpected instability in previously stable areas.

    Email from Julie Rama

    Subject: Refactoring Update – Regression and Stability Impact

    Hi,

    I wanted to provide an update on the architectural refactoring effort and flag some important developments.

    1. Refactoring Progress

    We have completed initial refactoring of:

    • Synchronization logic

    • Data validation flows

    • Selected module alignment changes

    These updates are now integrated into the current build.

    2. Regression Impact

    Following integration of these changes, we are observing:

    • 21 new defects identified in regression testing

      • 4 high severity

      • 9 medium

      • 8 low

    • Several previously resolved defects have reappeared

    • Increased inconsistency in system behavior across modules

    3. Performance Impact

    • Velocity: 85% of baseline

    • QA cycles significantly extended

    • Additional rework required across dependent components

    4. Schedule & Budget Impact

    • Estimated additional delay: +1–2 weeks beyond current projection

    • Additional effort: +6–8%

    • Burn rate trending upward again

    5. Vendor Perspective

    While these issues are expected in large-scale refactoring efforts, they are temporary and should stabilize once rework is complete.

    We recommend continuing with the current approach to fully align architecture rather than reverting changes.

    6. Request

    Please advise how you would like us to proceed:

    • Continue refactoring and stabilize system

    • Pause refactoring and prioritize stability

    • Limit refactoring scope further

    Best,
    Julie

    Attachment A – Defect Comparison

    Metric Before Refactoring After Refactoring
    Total Defects 10 31
    High Severity 0 4
    Reopened Defects 0 6

    Attachment B – Performance Snapshot

    Metric Status
    Velocity 85% baseline
    QA Effort Significantly increased
    Schedule Additional delay emerging
    Budget Increasing beyond prior trend

    Student Assignment

    You are the Project Manager at C-Bay.

    A decision to improve architectural integrity has resulted in:

    • Regression defects

    • Reduced velocity

    • Increased cost

    • Additional schedule pressure

    You must now decide:

    • Whether to continue refactoring

    • Whether to pause and stabilize

    • Whether to adjust strategy

    • How to manage risk introduced by your previous decision

    Prepare a formal written response to Julie Rama.

    Required Submission Structure

    Your memorandum must include:

    1️⃣ Executive Position

    • Is the project still under control?

    • Is current instability acceptable?

    • Should refactoring continue or be adjusted?

    2️⃣ Impact Assessment

    • What is the significance of regression defects?

    • How serious is the reintroduction of previously resolved issues?

    • Is this expected or excessive?

    3️⃣ Strategy Adjustment Decision

    Choose and justify:

    • Continue full refactoring

    • Pause refactoring and stabilize system

    • Reduce scope of refactoring

    • Phase refactoring more gradually

    4️⃣ Schedule & Budget Position

    • Is additional delay acceptable?

    • Is cost increase justified given long-term benefit?

    • Should limits be enforced?

    5️⃣ Risk Assessment

    Identify and evaluate:

    • Regression risk

    • System instability risk

    • Delivery delay risk

    • Budget escalation risk

    Assign likelihood and impact.

    6️⃣ Lessons from Prior Decision

    • What assumptions from the previous scenario proved incorrect?

    • How should decision-making be adjusted moving forward?

    7️⃣ Directive to ZynoxDev

    Provide a clear directive, such as:

    • Continue refactoring with increased QA controls

    • Pause refactoring and restore system stability

    • Focus only on critical architectural fixes

    • Introduce staged rollback or containment strategy

    Learning Focus

    Scenario 17 introduces:

    • Consequences of architectural intervention

    • Regression risk management

    • Managing unintended outcomes

    • Adjusting strategy mid-execution

    • Owning prior decisions

    Students must demonstrate:

    • Adaptability

    • Accountability

    • Systems thinking

    • Decision refinement under pressure

    Key Insight

    Fixing the system can break the system.

    Every improvement introduces risk.

    The Project Manager must manage:

    Not just what to change — but how and when to change it.

    This scenario reinforces:

    Second-order effects define real project complexity.

     

    4.5.18: Scenario 17 – Refactoring Impact and Regression Instability is shared under a CC BY 4.0 license and was authored, remixed, and/or curated by LibreTexts.