Bufferttid

Bufferttid is a term used in scheduling and process management to denote an amount of time deliberately set aside to absorb variability and delays in a plan or process. It acts as a cushion against uncertainty, helping to keep overall timelines intact even when individual tasks run longer than expected. It is related to, but distinct from, the total slack available in a schedule and from task durations.

In project management, buffertid is common in methods such as critical chain project management (CCPM) and traditional risk management. It can be applied at different levels, including task-level buffers, feeding buffers, and a project buffer at the end of the chain to protect the final delivery date. In manufacturing, buffertid helps accommodate variability in setup times, machine reliability, or changeovers. In software development or IT operations, buffer time can be used to handle integration, testing, or deployment delays.

Calculation approaches vary: some use a fixed percentage of planned duration, others rely on risk assessments and historical performance. Dynamic buffers can adjust as the project evolves. Buffers are typically monitored and consumed as work progresses, sometimes described via a buffer burn rate. Without discipline, buffers may become a justification for optimistic planning.

Bufferttid is related to concepts such as contingency, safety margin, and slack time, but serves a distinct purpose as a deliberate cushion. It should not be confused with buffer stocks in inventory management, which are units kept on hand. Overall, bufferttid aims to improve reliability by absorbing uncertainty, while requiring careful management to avoid over- or underestimation.