Big4 Audit Methodology

The Big4 audit methodology family models how the four largest global audit networks — EY (Global Audit Methodology), PwC (Aura), KPMG (Clara), and Deloitte (Omnia) — execute a financial-statement audit on top of a shared ISA-derived spine. The spine codifies the lowest common denominator across firms: a four-phase engagement lifecycle (planning, risk assessment and response, fieldwork, and evaluation / reporting) with seventeen named procedures that every Big4 engagement runs in some form. Per-firm overlays then capture the methodology divergences — proprietary procedure names, additional control-environment work, and firm-specific evidence templates — without forking the spine. A cross-firm equivalence map links every spine procedure to its named counterpart at each firm so you can navigate from one firm's vocabulary into another's. Use this family when you need a normalised view of how Big4 engagements run end-to-end, or when comparing methodologies across audit RFPs.