TIMWOODS Waste #4: Waiting – Idle Time that Undermines Airline Efficiency

How much time do your operations spend waiting instead of creating value?

In airline operations, timing is critical—aircraft rotations, maintenance windows, crew schedules, and passenger connections all depend on precise coordination. Yet, delays are not always caused by major disruptions. Many are the result of time lost waiting within processes.

Waiting waste occurs when people, equipment, or processes are idle because the next step is not ready. While often accepted as part of operations, it directly impacts efficiency, costs, and reliability.

In Lean, waste refers to any activity or resource that does not add value to the customer or the process. For an introduction to the TIMWOODS types of waste, see our previous article.

Understanding Waiting Waste

Waiting waste occurs when a process cannot move forward because something is missing—parts, tools, information, approvals, or resources.

These delays are often built into daily operations and become normalized over time.

Examples in aviation include:

• A pilot waiting for an aircraft to be released from maintenance

• A mechanic waiting for tools, equipment, or spare parts

• A component request waiting for internal approval or supplier confirmation

• Aircraft ground time extended due to coordination delays between teams

Each instance may seem minor on its own, but across operations, the accumulated impact can be significant.

In many cases, delays in one area create ripple effects across the system, affecting schedules, resource utilization, and overall performance.

Waiting is often the most interconnected type of waste, because many other inefficiencies ultimately cause idle time.

Why Waiting Waste Persists

Waiting waste rarely has a single cause. It typically results from disconnections between process steps and poor synchronization across functions.

Common causes include:

• Poor planning and scheduling — tasks are not aligned with resource availability

• Lack of coordination — dependencies between teams are not properly managed

• Delayed decision-making — approvals or authorizations slow down process flow

• Resource constraints — limited availability of tools, parts, or personnel

• Information gaps — missing or late data prevents the next step from starting

Because waiting is often seen as “part of the job,” it is rarely challenged or systematically reduced.

The Hidden Impact of Waiting Waste

Waiting waste is not just idle time—it affects the entire operation:

• Reduced productivity — resources are available but not being used effectively

• Increased operational costs — delays lead to inefficiencies and potential penalties

• Disrupted schedules — small delays accumulate and impact overall planning

• Frustration and disengagement — teams spend time waiting instead of working

• Knock-on effects — delays in one area create congestion or inefficiencies elsewhere

In aviation, where operations are tightly interconnected, waiting waste can quickly propagate across multiple functions.

Lean Approaches to Reduce Waiting Waste

Reducing waiting waste is not about working faster—it is about ensuring that work flows continuously without unnecessary interruptions.

Key approaches include:

• Improving planning and scheduling: Align tasks with resource availability to avoid gaps between steps

• Enhancing coordination: Ensure clear communication and synchronization across teams and functions

• Streamlining decision-making: Reduce delays in approvals and authorizations

• Ensuring resource availability: Position tools, parts, and personnel where and when they are needed

• Standardizing work: Create predictable workflows that reduce uncertainty and delays

• Designing for flow: Structure processes so that work progresses smoothly from one step to the next

The objective is to create a stable and continuous flow of work, where interruptions are minimized and resources are effectively utilized.

Reflection

Consider one operational process in your organization:

• Where does waiting occur between steps?

• What is causing the delay?

• How much of this waiting could be eliminated through better coordination or planning?

Waiting waste is often hidden within normal operations. Once identified, even small improvements can significantly enhance efficiency and reliability.

Learn how to identify and eliminate waste in airline operations with Lean principles →