Big4 Audit Methodology

The Big4 audit methodology family models a financial-statement audit on a shared, ISA-derived spine — the common ground that underlies the well-known firm methodologies (EY GAM, PwC Aura, KPMG Clara, Deloitte Omnia). The spine codifies a four-phase engagement lifecycle (planning, risk assessment and response, fieldwork, and evaluation / reporting) with seventeen named procedures drawn from the public international auditing standards. Standards-based methodology profiles aligned with each well-known methodology then express the engagement entirely in public ISA/PCAOB terms — they do not reproduce any firm's proprietary internal procedures or evidence templates. An equivalence map links every spine procedure to its counterpart across the profiles on that common, public-standard baseline. Use this family when you need a normalised, standards-based view of how an engagement runs end-to-end, or when comparing methodology coverage across audit RFPs.