When to use it
Use dependency logic when dates depend on other deliverables, approvals or external events.
Do not use unexplained lags to conceal work, and do not assume all dependencies are finish-to-start.
Apply it
The displayed inequality describes a dependency, not a complete schedule. Other relationship types constrain starts or finishes differently.
- Name the predecessor and the condition it must satisfy.
- Choose the relationship and explain any lead or lag.
- Check the resulting dates against calendars, resources and practical access.
An example in practice
A test can start only when a reviewed configuration is available. Model the review as work with an owner rather than hiding it inside a waiting period.
Source & credit
Common scheduling practice. The critical-path method is associated with James E. Kelley Jr. and Morgan R. Walker; their 1959 paper is the historical reference.
GAO: Schedule Assessment Guide
This explanation and example are independently written. The source is a reading reference; linking it does not grant permission to reuse its text, figures or assessments.