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</head>
<body>
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<div class="page">
<aside class="sidebar">
<div class="sidebar-top">
<h1>Devis Saputra</h1>
<p class="tagline">Learning Designer | AIEd</p>
<nav class="toc" aria-label="Systems engineering page navigation">
<a href="index.html">← Main Portfolio</a>
<a href="#overview">Overview</a>
<a href="#system-engineering">Empirical Studies <i class="fa-brands fa-github" aria-hidden="true"></i></a>
</nav>
</div>
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<div class="contact-label">Links</div>
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<i class="fa-brands fa-xing" aria-hidden="true"></i><span>Xing</span>
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<i class="fa-brands fa-github" aria-hidden="true"></i><span>GitHub</span>
</a>
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<i class="ai ai-orcid" aria-hidden="true"></i><span>ORCID</span>
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<a class="back-link" href="index.html"><i class="fa-solid fa-arrow-left" aria-hidden="true"></i> Back to main portfolio</a>
<div class="portfolio-nav" aria-label="Portfolio areas">
<a href="research.html">Research</a>
<a href="learningdevelopment.html">Learning & Development</a>
<a href="aiengineering.html">AI Engineering</a>
<a href="aieducation.html">AI in Education</a>
<a href="systemsengineering.html" class="active" aria-current="page">Systems Engineering</a>
</div>
<section class="hero" id="overview">
<h2>Systems Engineering</h2>
<p class="lede">Four empirical studies in engineering trade spaces, requirements, performance monitoring and engineering change.</p>
<div class="item-index empirical-index" aria-label="Systems engineering studies">
<a href="#empirical_engineering_tradespace">Trade Space</a>
<a href="#requirements_evidence_triage">Requirements Triage</a>
<a href="#technical_performance_margin_monitor">Battery Prognostics</a>
<a href="#engineering_change_dynamics">Engineering Change</a>
</div>
</section>
<!-- SYSTEM ENGINEERING EMPIRICAL STUDIES START -->
<section class="repo-section" id="system-engineering">
<div class="eyebrow-rule bundle-heading"><h2>Empirical Studies <i class="fa-brands fa-github section-title-icon" aria-hidden="true"></i></h2></div>
<article class="repo-project research-bundle" id="empirical_engineering_tradespace">
<div class="repo-project-grid">
<div class="repo-visuals">
<figure class="repo-visual">
<img loading="lazy" src="assets/research/system_engineering/empirical_engineering_tradespace/research_design.svg" alt="Empirical Engineering Design Trade Space: Concrete Slump Experiments: scientific system overview">
<figcaption>Scientific system overview</figcaption>
</figure>
<figure class="repo-visual">
<img loading="lazy" src="assets/research/system_engineering/empirical_engineering_tradespace/method.svg" alt="Empirical Engineering Design Trade Space: Concrete Slump Experiments: data processing pipeline">
<figcaption>Data processing and empirical workflow</figcaption>
</figure>
</div>
<div>
<div class="repo-kicker">Systems Engineering</div>
<h3>Empirical Engineering Design Trade Space: Concrete Slump Experiments</h3>
<div class="repo-copy">
<p>Using 103 observed concrete mixture experiments, the analysis treats the laboratory observations as a systems engineering trade space. Pareto efficient alternatives are identified across cement use, slump and 28 day compressive strength.</p>
<p>A second formulation removes slump from the objective set and then treats it as an eligibility threshold. Comparing the resulting Pareto sets shows how strongly the engineering decision space depends on the definition of requirements.</p>
</div>
<div class="repo-data-note"><strong>Data source:</strong> UCI Concrete Slump Test, 103 laboratory mixture experiments, DOI 10.24432/C5FG7D.</div>
<div class="repo-links">
<a href="https://github.com/devissaputra/empirical_engineering_tradespace" target="_blank" rel="noopener noreferrer"><i class="fa-brands fa-github" aria-hidden="true"></i> Repository</a>
<a href="https://github.com/devissaputra/empirical_engineering_tradespace/blob/main/REPORT.md" target="_blank" rel="noopener noreferrer"><i class="fa-solid fa-file-lines" aria-hidden="true"></i> Report MD</a>
<a href="https://github.com/devissaputra/empirical_engineering_tradespace/blob/main/docs/paper_blueprint.md" target="_blank" rel="noopener noreferrer"><i class="fa-solid fa-file-pen" aria-hidden="true"></i> Paper</a>
<a href="https://github.com/devissaputra/empirical_engineering_tradespace/blob/main/data/README.md" target="_blank" rel="noopener noreferrer"><i class="fa-solid fa-database" aria-hidden="true"></i> Data source</a>
</div>
</div>
</div>
</article>
<article class="repo-project research-bundle" id="requirements_evidence_triage">
<div class="repo-project-grid">
<div class="repo-visuals">
<figure class="repo-visual">
<img loading="lazy" src="assets/research/system_engineering/requirements_evidence_triage/research_design.svg" alt="Requirements Classification Evidence Triage on a Gold Standard Benchmark: scientific system overview">
<figcaption>Scientific system overview</figcaption>
</figure>
<figure class="repo-visual">
<img loading="lazy" src="assets/research/system_engineering/requirements_evidence_triage/method.svg" alt="Requirements Classification Evidence Triage on a Gold Standard Benchmark: data processing pipeline">
<figcaption>Data processing and empirical workflow</figcaption>
</figure>
</div>
<div>
<div class="repo-kicker">Systems Engineering</div>
<h3>Requirements Classification Evidence Triage on a Gold Standard Benchmark</h3>
<div class="repo-copy">
<p>The requirements classification analysis uses 571 eTour requirement elements and evaluates fine grained classification performance. It also examines how limited human review effort could be allocated when errors are unevenly distributed across requirement categories.</p>
<p>Gold labels are used only for retrospective diagnosis and to define an oracle ceiling. The operational review queue is ranked from model outputs without access to the answer key. The comparison quantifies both the potential value of targeted review and the gap between retrospective error knowledge and a deployable triage procedure.</p>
</div>
<div class="repo-data-note"><strong>Data source:</strong> eTour gold standard requirements benchmark and pinned NoRBERT/FTLR replication artifacts hosted through Zenodo.</div>
<div class="repo-links">
<a href="https://github.com/devissaputra/requirements_evidence_triage" target="_blank" rel="noopener noreferrer"><i class="fa-brands fa-github" aria-hidden="true"></i> Repository</a>
<a href="https://github.com/devissaputra/requirements_evidence_triage/blob/main/REPORT.md" target="_blank" rel="noopener noreferrer"><i class="fa-solid fa-file-lines" aria-hidden="true"></i> Report MD</a>
<a href="https://github.com/devissaputra/requirements_evidence_triage/blob/main/docs/paper_blueprint.md" target="_blank" rel="noopener noreferrer"><i class="fa-solid fa-file-pen" aria-hidden="true"></i> Paper</a>
<a href="https://github.com/devissaputra/requirements_evidence_triage/blob/main/data/README.md" target="_blank" rel="noopener noreferrer"><i class="fa-solid fa-database" aria-hidden="true"></i> Data source</a>
</div>
</div>
</div>
</article>
<article class="repo-project research-bundle" id="technical_performance_margin_monitor">
<div class="repo-project-grid">
<div class="repo-visuals">
<figure class="repo-visual">
<img loading="lazy" src="assets/research/system_engineering/technical_performance_margin_monitor/architecture.svg" alt="NASA battery capacity trajectories with fixed monitoring checkpoints and 1.4 Ah end of life boundary">
<figcaption>NASA capacity trajectories and monitoring checkpoints</figcaption>
</figure>
<figure class="repo-visual">
<img loading="lazy" src="assets/research/system_engineering/technical_performance_margin_monitor/method.svg" alt="Fixed checkpoint technical performance margin forecasting and evaluation pipeline">
<figcaption>Fixed checkpoint forecasting and evaluation workflow</figcaption>
</figure>
</div>
<div>
<div class="repo-kicker">Systems Engineering</div>
<h3>Forecast Maturity of Technical Performance Margin on NASA Lithium Ion Battery Aging Data</h3>
<div class="repo-copy">
<p>Four NASA lithium ion battery trajectories are evaluated at fixed cycle checkpoints to study the maturity of technical performance margin forecasts. Each forecast is restricted to information available at the corresponding checkpoint, preserving the temporal conditions of an actual engineering decision.</p>
<p>At each checkpoint, the analysis records current capacity margin, projected crossing of NASA’s 1.4 Ah end of life criterion, subsequent forecast revision and realized forecast error. Aggregate error declines as evidence accumulates, but behavior differs across cells and one battery produces an early false warning. Forecast stability therefore becomes part of the evidence used to judge decision readiness.</p>
</div>
<div class="repo-data-note"><strong>Data source:</strong> NASA Prognostics Center of Excellence Lithium Ion Battery Data Set, using cells B0005, B0006, B0007, and B0018.</div>
<div class="repo-links">
<a href="https://github.com/devissaputra/technical_performance_margin_monitor" target="_blank" rel="noopener noreferrer"><i class="fa-brands fa-github" aria-hidden="true"></i> Repository</a>
<a href="https://github.com/devissaputra/technical_performance_margin_monitor/blob/main/REPORT.md" target="_blank" rel="noopener noreferrer"><i class="fa-solid fa-file-lines" aria-hidden="true"></i> Report MD</a>
<a href="https://github.com/devissaputra/technical_performance_margin_monitor/blob/main/docs/paper_blueprint.md" target="_blank" rel="noopener noreferrer"><i class="fa-solid fa-file-pen" aria-hidden="true"></i> Paper</a>
<a href="https://github.com/devissaputra/technical_performance_margin_monitor/blob/main/data/README.md" target="_blank" rel="noopener noreferrer"><i class="fa-solid fa-database" aria-hidden="true"></i> Data source</a>
</div>
</div>
</div>
</article>
<article class="repo-project research-bundle" id="engineering_change_dynamics">
<div class="repo-project-grid">
<div class="repo-visuals">
<figure class="repo-visual">
<img loading="lazy" src="assets/research/system_engineering/engineering_change_dynamics/architecture.svg" alt="Ternary map of perfective, corrective, and other maintenance intent across 54 Apache projects">
<figcaption>Cross project maintenance intent composition</figcaption>
</figure>
<figure class="repo-visual">
<img loading="lazy" src="assets/research/system_engineering/engineering_change_dynamics/method.svg" alt="Reproducible pipeline for maintenance intent aggregation, heterogeneity testing, sensitivity, and diagnostics">
<figcaption>Heterogeneity analysis and diagnostic workflow</figcaption>
</figure>
</div>
<div>
<div class="repo-kicker">Systems Engineering</div>
<h3>Cross Project Heterogeneity in Quality Oriented Engineering Change</h3>
<div class="repo-copy">
<p>The analysis reexamines 2,533 manually classified commits from 54 Apache Java projects to determine whether a pooled maintenance profile represents individual software systems adequately. Each project is characterized by its observed proportions of perfective, corrective and other maintenance intent, together with uncertainty at the project level.</p>
<p>Cross project heterogeneity is quantified, tested again after progressively removing small project samples and decomposed into the project and category combinations contributing most strongly to the overall statistic. The results show that a pooled portfolio average can conceal substantial differences among individual project maintenance profiles.</p>
</div>
<div class="repo-data-note"><strong>Data source:</strong> Trautsch, Erbel, Herbold & Grabowski replication dataset on Zenodo, DOI 10.5281/zenodo.7078179.</div>
<div class="repo-links">
<a href="https://github.com/devissaputra/engineering_change_dynamics" target="_blank" rel="noopener noreferrer"><i class="fa-brands fa-github" aria-hidden="true"></i> Repository</a>
<a href="https://github.com/devissaputra/engineering_change_dynamics/blob/main/REPORT.md" target="_blank" rel="noopener noreferrer"><i class="fa-solid fa-file-lines" aria-hidden="true"></i> Report MD</a>
<a href="https://github.com/devissaputra/engineering_change_dynamics/blob/main/docs/paper_blueprint.md" target="_blank" rel="noopener noreferrer"><i class="fa-solid fa-file-pen" aria-hidden="true"></i> Paper</a>
<a href="https://github.com/devissaputra/engineering_change_dynamics/blob/main/data/README.md" target="_blank" rel="noopener noreferrer"><i class="fa-solid fa-database" aria-hidden="true"></i> Data source</a>
</div>
</div>
</div>
</article>
</section>
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