Methodology · evidence to decision

Evidence you can inspect.

Trace each finding to evidence and each estimate to its assumptions. Challenge the recommendation before deciding.

Published method Constructed example Limits included
Dr Zak OuzzifWork directly with
Dr Zak Ouzzif
A stack of books with their pages facing outward.

The complete chain

Five steps. No black box.

Measurement and judgment stay separate so your team can challenge the estimate without losing the evidence.

Collect

Interfaces, requirements, tests, decisions, changes, and defects.

Connect

Show where dependencies cross system and ownership boundaries.

Quantify

Use your change history to estimate excess effort and delay.

Stress-test

Vary assumptions and expose what moves the result.

Decide

Fund, measure, defer, or leave alone.

Use the records you already have.

Inputs

Use the records you already have.

Source code sharpens the map when available. It is not the only place system design evidence lives.

Interface records

Boundaries, contracts, and coupling edges.

Core input

Requirements

Allocation and traceability across modules.

Core input

Change history

Effort weighting for the exposure model.

Preferred

Test evidence

Where failures and verification effort concentrate.

Preferred

Decision records

Known compromises, waivers, and deferred work.

Preferred

Source repository

Confirms whether documented boundaries match reality.

Optional
The evidence behind the method.

Published research

The evidence behind the method.

Two studies, two different questions.

Document evaluation

How well did the classifier perform?

Aerospace documentsClassification test
Documents
141
F1 score
0.82
Cohen’s κ
0.84

Scores describe classification performance and agreement, not cost-model accuracy.

Evaluation: §4.1.1 / Table 4.1, pp. 39–40 ↗

Separate practitioner feedback

What did practitioners report?

PractitionersExpert survey
Survey participants
35

The 35-person survey is separate from the document population behind the classifier scores.

Survey: §4.3, pp. 47–56 ↗

Financial decisions need case-specific evidence. Classification scores and practitioner feedback support different parts of the assessment.

The published evaluation covers technical-debt classification in aerospace test-and-evaluation documents; organizational and AI-adoption applications require separate validation.

Scope of the published research

Ouzzif, Zakaria (2026), A Technical Debt Management Framework for Aerospace Systems Engineering: An AI-Driven Approach to Test and Evaluation Documentation Analysis, PhD dissertation, Worcester Polytechnic Institute, May 2026.

Page 62 defines the study scope and the evidence needed for broader application.

AI-generated illustration of hands mapping a workflow on a desk.AI-generated illustration of two people checking an AI draft against a customer request.

Constructed exposure model

Change the assumptions. Watch the estimate move.

This illustration starts with 1,200 engineering days at a $650 loaded day rate. Real assessments use your records and publish a range—not a false point estimate.

Illustrative modelNot client data
Effort versus a low-coupling baseline
Share of annual change effort
Excess days497
Annual exposure$323k
Schedule5.5 wk
$262kSensitivity band$363k

The coupling multiplier dominates this example. Better module-level change data narrows the band.

Concentration becomes a ranked plan.

What the model produces

Concentration becomes a ranked plan.

Constructed figures demonstrate the format only. They are not a client result, benchmark, or promise.

01 · Locate

Change effort concentration

71%of effort
Modules18
Cluster4 modules
Interfaces62%
02 · Rank

Return per engineering day

  1. 01
    Re-partition A–B boundaryHighest exposure removed per day
    Fund
  2. 02
    Extract shared stateCredible intervention and payback
    Fund
  3. 03
    Instrument supplier changesEvidence needs narrowing first
    Measure
  4. 04
    Rewrite low-change internalsWeak return despite visible debt
    Leave

Keep confidence separate from coverage.

Expected

Expected.
Constructed specimen confidence by source, not research validation scores. Coverage uses different units and remains in the sample evidence table. Units: %.
Interfaces
91
Change history
86
Source checks
64
Review records
82
Effort attribution
48
Interviews
78

Limits

The boundary is part of the method.

Open the caveat that matters. Each one is raised during scoping and shown again in the report.

Classification is not cost accuracy

κ 0.84 and F1 0.82 describe repeatability. The cost range depends on the economic assumptions tested separately.

Evidence quality controls confidence

Missing or outdated records widen the range. Source access can confirm whether documented boundaries match the implementation.

Causal evidence is not a controlled experiment

The model compares high- and low-coupling work inside the same organization. It supports a causal argument; it does not claim experimental proof.

The result is point-in-time decision support

System design continues to change. The assessment is not certification evidence and does not replace an auditor, DER, or safety assessor.

Control the evidence before it moves.

Material handling

Control the evidence before it moves.

Transfer, access, retention, and deletion are agreed in writing before the assessment begins.

Access

Minimum necessary

Limit material and people to the agreed system boundary.

Environment

Work in place

Scope work inside your environment where transfer is impractical.

Reuse

Never

No model training, benchmarking, or reuse in another engagement.

Deletion

Confirmed

Destroy material on the agreed date and confirm it in writing.

Dr Zak Ouzzif

About the practitioner

Dr Zak Ouzzif, principal consultant at ZOYA Solutions

Dr Zak Ouzzif

Principal architect · ZOYA Solutions

Experience with critical defense systems informs how I examine dependencies, test changes, and plan for continuity. I apply that judgment to business improvement and practical AI.

My doctoral research in systems engineering produced the Technical Debt Management Framework (TDMF), built to bridge the gap between academic rigor and executive decision-making. My approach translates deep systems engineering theory into pragmatic, executable risk assessments.

I founded ZOYA Solutions on a simple structure: advisory and delivery are separate scopes with an explicit investment decision between them. The diagnostic and the business case stand on their own — you can act on the roadmap yourself, hand it to another partner, or ask us to implement it.

When we do implement, it is scoped and quoted separately, after the evidence is already yours.

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