Occupational certification requires defensible evidence of knowledge, practical capability and performance in context. South Africa’s External Integrated Summative Assessment (EISA) provides independent national assessment, alongside internal assessment and workplace evidence required for eligibility. This conceptual review examines how these evidence streams could inform a more transparent final competence decision. Fifteen purposively selected academic and policy sources provide assessment theory, vocational evidence and policy context; they do not constitute a systematically screened corpus. The synthesis distinguishes evidence from technical and vocational education and training from principles transferred from medical education. It identifies construct coverage, evidence authentication, reproducibility of judgement and unequal workplace opportunities as central design problems. An Integrated Competence Evidence Model is proposed, combining mapped portfolio records, workplace performance, provider assessment and independent external assessment. The portfolio functions as an evidence repository rather than a separately scored domain, preventing the same performance from being counted twice. Universal percentage weightings are replaced by mandatory competence requirements and qualification-specific calibration. Operational definitions specify evidence sufficiency, authenticity and moderation, while a prospective pilot sets out independent assessment, follow-up workplace observation, reliability analysis and feasibility evaluation. The model is a testable policy proposal, not a validated replacement for EISA. Its value depends on demonstrating stronger decisions without weakening national standards or imposing disproportionate costs.