Spare parts inventory and customer escalations continue to rise despite increasing investment, according to Unilog.SC’s June 2026 Industry Research Report, Service Parts Network Design.
In fact, network design, not inventory investment, is noted as the critical factor in translating service commitments into customer outcomes and aftermarket performance.
According to the report, manufacturers tie up approximately 10% of annual sales in spare parts inventory. Meanwhile, customer satisfaction with after-sales support runs 10-15% below expectation. In many networks, nearly half of service calls are delayed because the required part is not available in the right location when needed.
“The industry has spent years focusing on inventory levels, SLAs, and cost reduction, but many organizations are still struggling to improve service outcomes,” says Eyal Yossef, VP supply chain solutions at Unilog. “Our research shows that network design, not inventory investment, is what determines whether service commitments translate into customer uptime and profitability. The companies that will outperform over the next decade will be those that treat service availability as a designed outcome.”
Key takeaways:
· Rising inventory and rising customer escalations are often a result of the same network design problem.
· Service parts networks should be managed as connected chains rather than traditional warehouse hierarchies.
· Parts stocking decisions should be based on criticality and demand variability, not just unit cost.
· Service-level agreements must be supported by differentiated stocking policies, replenishment strategies, and fulfillment models.
· Organizations that focus solely on average service performance can overlook high-impact failures tied to slow-moving, mission-critical parts that drive customer dissatisfaction, contract risk, and costly escalations.
