What are the methods for construction delay analysis?

Delay analysis methods: (1) As-planned vs as-built - compare original schedule to actual, simple but doesn't consider concurrency, (2) Impacted as-planned - add delays to as-planned schedule, shows delay impact, (3) Collapsed as-built - remove delays from as-built, shows but-for duration, (4) Time impact analysis - insert delays into schedule updates contemporaneously, most accurate, (5) Windows analysis - divide project into periods, analyze each window. Selection depends on schedule quality, documentation, and claim requirements. Analysis requires understanding of critical path and concurrent delays.