By Paul R Salmon FCILT, FSCM
In complex supply chains, every decision about how materials flow impacts availability, cost, and responsiveness. One deceptively simple practice – batching unserviceable items before sending them for repair – is a prime example. While it can feel efficient in isolation, it creates hidden delays, drives excessive inventory, and reduces overall system agility.
For supply chain leaders seeking to improve performance, breaking the batching habit is a critical step.
🔄 How Batching Repairs Bloats Inventory
When an item fails in service, there are two possible approaches:
Continuous Return: Each failed item is sent for repair immediately. Batch Return: Failed items are stockpiled until a pre-determined number is reached (e.g., a truckload or pallet), and then sent together.
Batching often seems cost-effective because it:
✅ Reduces transport costs per unit.
✅ Simplifies administration by handling groups rather than individual returns.
✅ Minimises disruption at the repair facility by avoiding frequent deliveries.
But this perceived efficiency comes at a price:
1️⃣ Longer Turnaround Times (TAT)
In a batch system, items sit idle waiting for enough failures to justify a shipment. Only then are they sent for repair and the clock on the repair process starts.
This artificial delay extends the time it takes to cycle repaired items back into the supply chain, forcing organisations to hold higher levels of spare inventory to maintain availability.
2️⃣ Higher Pipeline Inventory
If items spend days or weeks in a batching queue, they are effectively removed from the active pool. To keep the system running, supply chains must compensate by buying or holding more spares.
In other words, the inventory pipeline gets swollen with idle assets at multiple points:
Waiting to ship. In transit. In repair.
3️⃣ Reduced Asset Utilisation
For high-value components, slow repair cycles mean expensive assets sit unused. This is especially critical in defence, where platforms often rely on small pools of critical spares.
4️⃣ Bullwhip Effect Amplification
At the repair facility, batching creates lumpy, unpredictable inflows:
Long quiet periods are followed by surges of work. Workload planning becomes harder. Lead times fluctuate, further increasing safety stock requirements.
🛡 Defence Supply Chain Example
In military aviation, it’s common practice to wait until there are enough unserviceable avionics to fill a crate before shipping them to the OEM repair facility.
Impact: Each failed unit spends weeks sitting idle at the squadron or depot level. Meanwhile, the air fleet must be supported by a larger pool of spares to compensate for the slow turnaround.
By moving to piece-by-piece returns using scheduled backhaul flights, turnaround times can be slashed and inventory holdings reduced, freeing up capital for other priorities.
🛒 Civilian Supply Chain Example
In electronics retail, some companies used to batch returned smartphones until they had pallets full before shipping them to refurbishment centres.
Impact: Devices spent weeks in local warehouses, extending the cash conversion cycle and tying up working capital in unsellable stock. Solution: Companies like Apple adopted continuous reverse logistics, shipping smaller quantities more frequently. This enabled faster refurbishment, lower safety stock, and quicker resale – critical in a market where products rapidly lose value.
🛠 Breaking the Batching Habit
✅ 1. Shift to Continuous Returns
Ship failed components as soon as they are removed from service. Even if transport costs rise slightly, the savings in inventory and improved availability often dwarf these costs.
✅ 2. Use Consolidated Transport Networks
To offset higher shipping costs, use scheduled transport (e.g., daily or weekly runs) or leverage backhaul opportunities in existing logistics flows.
✅ 3. Monitor and Optimise TAT
Make turnaround time a key metric. Tie it directly to platform or system availability to drive awareness of the inventory impact of batching delays.
✅ 4. Collaborate with Repair Partners
Share real-time failure data with repair facilities to help them smooth workload planning and avoid being overwhelmed by batch arrivals.
📉 The Hidden Cost of Batching Repairs
The perceived efficiency of batching often masks real costs:
🕒 Extended downtime for high-value assets. 📦 Bloated inventory pipelines requiring higher safety stock. 💸 Capital locked up in idle components.
By moving towards flow-based repair loops, supply chains can unlock significant savings and improve responsiveness.
🖇 Key Takeaways for Supply Chain Leaders
✅ Batching repairs creates avoidable delays and inflates inventory.
✅ Continuous return practices can improve turnaround times and reduce the need for excess spares.
✅ Even if transport costs rise, total supply chain costs often fall when batching is eliminated.
✅ Defence and civilian organisations alike can benefit from rethinking their reverse logistics strategies.
