Delays

Delays are periods in which a planned event or process takes longer to complete than originally scheduled. In many contexts, a delay represents a lag between a target time and the actual time at which an action occurs or a result is delivered. Delays can be intentional or unintentional and may reflect a temporary setback or a longer-term postponement.

Common domains and causes

In transportation, delays refer to late departures or arrivals, including air, rail, and road travel. Causes include weather, equipment failures, air traffic congestion, and incidents on the route. In manufacturing and logistics, delays affect production schedules, procurement, and delivery lead times, arising from supplier disruptions, machine downtime, demand volatility, or transportation interruptions. In construction and project delivery, schedule slippage occurs when milestones or the critical path are extended due to funding gaps, permitting delays, or adverse weather. In information technology and communications, delays describe latency and buffering, where data packets or media streams take longer than expected to reach a destination, caused by network congestion, processing load, or hardware limitations.

Measurement and impact

Delays are typically measured in units of time and can be analyzed through metrics such as average delay, delay distribution, and end-to-end latency. Delays affect efficiency, costs, reliability, and customer satisfaction, and in some cases pose safety or contractual risks.

Mitigation

Common mitigation strategies include schedule buffers, risk assessment, contingency planning, process improvements, redundancies, and real-time monitoring to reduce the likelihood or impact of delays.