Legal Definitions - post-factum

Post-factum refers to something that occurs, is done, or is considered after an event or action has already taken place. It describes an act, decision, or analysis that follows the primary event or fact.

• Example 1: Incident Investigation

  After a significant software outage disrupts services for many customers, the company initiates a post-factum investigation. This involves reviewing system logs, interviewing engineers, and analyzing network traffic to understand precisely what went wrong and how to prevent similar incidents in the future.

  This illustrates post-factum because the investigation and analysis are conducted entirely after the outage (the "factum") has already occurred.

• Example 2: Policy Evaluation

  A city council implements a new zoning ordinance to encourage mixed-use developments. Two years later, they commission a post-factum study to assess the ordinance's actual impact on housing availability, traffic patterns, and local business growth, rather than relying solely on initial projections.

  Here, the study is post-factum because it evaluates the effects of the ordinance after it has been in effect for a period (the "factum" of its implementation and operation).

• Example 3: Contractual Amendment Attempt

  A construction company completes the foundation work for a new building as per an agreed-upon contract. Subsequently, the client attempts to introduce a new clause requiring the use of a more expensive, specialized concrete mix for the foundation, arguing it should apply post-factum to the work already finished.

  This demonstrates post-factum because the client is trying to apply a new condition or requirement after the original work (the "factum") has already been completed according to the initial agreement.