Value Stream Mapping for Container Depots and Empty Container Parks: From Truck Gate-In to Reusable Asset Without the Turn-Time Queue

1. Why value stream mapping matters in a container depot

In an empty container park, a returned container is not yet a reusable asset. It must be accepted, inspected, routed to the right process, repaired or washed where required, and placed where it can be found for its next use. Meanwhile, the driver needs a safe, predictable visit and the depot must balance yard capacity, equipment availability and repositioning demand.

Value stream mapping makes these connected activities visible. It captures both the physical flow of the container and the information flow that directs it: pre-advice, gate validation, condition records, repair approvals, yard locations and release status. The aim is to understand the whole process, not optimise one station while creating delays elsewhere.

For this guide, the value delivered is a compliant, correctly classified, reusable container available at the right location. Truck turn time matters, but it is only one part of the performance picture. A fast truck visit does not guarantee fast container release if the asset then waits days for an inspection decision, parts, a wash bay or an accessible yard slot.

2. Select a clear product family and scope

Begin with one repeatable flow: import container de-hire and empty repositioning through a metropolitan depot. Keep export hire, reefers, quarantine or other specialised flows separate initially if they have materially different requirements. They can be mapped as connected or separate families after the team understands this baseline.

Set the boundaries as follows:

• Start: the returned container and truck arrive at the depot gate.
• Finish: the inspected container is released into the correct available inventory class, ready for a confirmed next movement.
• Include: pre-advice, gate-in, unload, inspection, exception routing, repair or wash, yard placement and release.
• Track separately: truck turn time and the container’s elapsed time to reusable status.

Form a cross-functional team with gate staff, surveyors, M&R (maintenance and repair), wash-bay operators, yard planners, dispatch, customer or equipment-owner representatives, and drivers where practical. Validate the map through direct observation and timestamps, not process documentation alone. For a practical overview of mapping steps, see our detailed process mapping guide.

3. Current-state map: a worked baseline

The following figures are illustrative, not industry benchmarks. They represent a hypothetical metropolitan depot processing 1,200 de-hires per month across 20 operating days: around 60 containers per day. Measure your own peak and off-peak performance before setting targets.

The material flow is:

Truck arrival → gate validation → unload → condition inspection → release, repair, wash or hold → yard placement → reusable status

The information flow begins with the carrier or customer’s pre-advice and continues through identity checks, damage coding, approval, treatment evidence, yard location and release confirmation.

Define each metric before collecting data. For example, truck turn time here begins at gate authorisation, while the pre-gate queue is measured separately. The container’s 6.4-day lead time ends when it reaches reusable status; it is not the same measure as the driver’s visit. The 47 minutes of touch time is a weighted process estimate, not 47 minutes of continuous work. Most elapsed time is waiting between steps.

Problem statement

Over a 20-operating-day baseline, the depot handles approximately 60 de-hire containers per day. Average authorised-to-exit truck turn is 84 minutes, while average gate-in to reusable status is 6.4 days. Inspection is first-time-right for 86% of units; washing demand exceeds throughput by 12 containers per day; and peak slot demand exceeds usable capacity by 120 spaces. The improvement opportunity is to reduce avoidable waiting and rehandling while maintaining safety, inspection quality, customer requirements and reliable asset release.

This statement is specific enough to guide a DMAIC project: it identifies the process, baseline, performance gap and constraints without assuming the root cause.

4. Identify the eight wastes: DOWNTIME

Walk the yard and follow selected containers end to end. Use the DOWNTIME acronym to organise observations, then verify the scale of each issue with data.

• Defects: incomplete damage codes or inspection records trigger reinspection, correction or incorrect routing.
• Overproduction: washing or repairing units before confirming the required condition standard or likely next use creates work that may not be needed.
• Waiting: drivers queue for gate processing; containers wait for inspection, repair approval, parts or a wash slot.
• Non-utilisation of talent: experienced surveyors and operators spend time chasing status or re-entering information instead of applying their process knowledge.
• Transportation: containers move between survey, workshop, wash and stack areas without a flow-based route.
• Inventory: damaged, awaiting-approval and ready-to-use boxes occupy scarce slots; high occupancy makes the right unit harder to access.
• Motion: workers search for records, tools, parts or container locations because information and materials are not organised at point of use.
• Extra-processing: duplicate checks, repeated data entry, unnecessary approvals and repeated handling add effort without improving the container’s condition or service value.

5. Build the future state around flow

The future state should make routine work predictable and exceptions visible. Design countermeasures with frontline staff, test them on a defined area or shift, and check effects on both truck and asset performance.

1. Pre-advice and digital pre-gate: require container ID, owner, size/type and relevant handling instructions before arrival. Match the record at entry and route exceptions to a staffed resolution point.
2. Slot booking: smooth arrivals against gate, inspection and yard capacity. Track appointment adherence and retain a controlled way to handle urgent or unplanned arrivals.
3. Triage-based inspection: use agreed condition codes and a standard photo checklist. Route units promptly to release, wash, repair or hold; keep safety and quality criteria unchanged.
4. Repair standard work and parts kitting: standardise assessment, estimate, authorisation and quality check. Kit frequently used parts for planned work and make approval status and ownership visible.
5. Yard zoning by flow: create clearly identified zones for ready units, awaiting repair, wash, approval and other controlled holds. Use planned locations and access rules to reduce searching and rehandles.
6. Visual management of dwell: display age by status, exception owner and escalation point. Review aged boxes daily, alongside gate performance, wash capacity and yard occupancy.

For a sense of what automation may achieve in a specific setting, the Victorian Empty Container Park Trial report reported a 17.7-minute average peak truck turn time at medium- and high-automation trial sites. Treat this as a finding from that trial, not a universal target for depots with different boundaries, technology or operating conditions.

6. Current state versus a testable future state

These future-state figures are proposed pilot targets, not promised outcomes. Confirm feasibility against local arrival patterns, safety requirements, labour coverage, owner approvals and asset mix.

Do not pursue the turn-time target by shifting congestion into the yard or weakening inspection. Review median and 90th-percentile times, first-time-right rate, aged dwell, rehandles, wash output and safety indicators together. This is the systems view at the heart of value stream mapping.

7. Sequence the kaizen work over 90 days

Days 1–15, Establish the baseline: confirm definitions, observe peak and off-peak shifts, timestamp each handoff, verify slot counts and segment dwell by status. Validate the current-state map with depot staff and transport partners.

Days 16–30, Address visibility and simple standards: trial a common inspection checklist and damage codes. Introduce a daily aged-dwell review, clarify exception ownership and test pre-advice completeness.

Days 31–60, Pilot flow changes: test booked arrivals or digital pre-gate on selected shifts. Trial triage routing, a fast path for units meeting release criteria, repair standard work and parts kitting. Use defined yard zones with clear location rules.

Days 61–75, Measure and refine: compare pilot and baseline periods on equivalent shifts. Review turn-time distribution, inspection quality, wash throughput, repair queue, slot utilisation and rehandles. Adjust countermeasures where they create a new constraint.

Days 76–90, Standardise and sustain: document proven standard work, train affected teams, assign KPI owners and establish visual controls and escalation triggers. Agree the next improvement cycle with depot leadership and partners.

Turn a depot map into a practical improvement capability

A well-built value stream map helps depot teams see how gate decisions, inspections, repair approvals, wash capacity and yard layout combine to determine service. The worked numbers above show how to define the baseline; local observation and validated data show where to act.

Build your capability with Lean Six Sigma certification from White Belt through Master Black Belt. Lean 6 Sigma Hub offers CSSC-accredited, self-paced online training with simulations, dummy data, worked examples and end-to-end case studies, including a complete DMAIC project. Develop skills to map processes, validate root causes and sustain measurable improvements.

Explore the certification pathway and choose your next Lean Six Sigma course.

Kaizen. Kai-Care. Kai-Done. Lean Six Sigma