In many companies, inventories remain stubbornly high. Occasionally, customer service is sacrificed, typically at year-end to flatter the balance sheet, but inevitably, once attention drifts elsewhere, then inventories drift too.
The only consistent pressure on inventory usually comes from the walls of the warehouse.
No one outside of Finance is really sorry.
Supply chain teams aren’t sorry because they need inventory to deliver to customers “on-time-in-full” – which is how they are measured. Manufacturing like to build inventory because it allows them to produce in large, efficient batches. They are measured by cost. Purchasing gets better prices if they buy in large quantities, and even Sales inflate their forecasts, just to make sure the products they sell will always be in stock.
In her Forbes article How Manufacturers Lost the Inventory Battle, Lora Cecere asserts that:-
“Today’s average manufacturing company carries thirty days more inventory than at the beginning of the 2007 recession.”
She goes on to explain that inventory is the most significant source of waste and the most important buffer for the supply chain. As variability increases, organizations experience tension in managing inventory trade-offs.
“Caught in a system of dysfunctional metrics, inventory piles grow as teams push for manufacturing efficiency. The management of inventory is typically the responsibility of everyone, and as a result, it becomes no one’s responsibility.
From 2004 to 2022, average global manufacturing inventories grew by thirty days. This is despite the increase in supply chain planning and Enterprise Resource Planning (ERP) investment. Supply Chain Insights research found that 93% of manufacturers greater than $500M in annual revenues deployed this type of technology.
There are three primary reasons for the increase
1. Rise In Product Complexity. Increasing product complexity increases manufacturing cycle stock requirements (the time to cycle through a product line in manufacturing).
2. Shifts In Sourcing Cycles. The lead time cycle increases due to global sourcing, manufacturing, and distribution outsourcing increased in-transit inventories. (Inventory on trucks, barges, containers, and third-party locations.) Leadtime variability over the last thirty-seven months acerbated the issues.
3. Increases In Demand Variability. As product complexity increased, product forecastability decreased, growing the need for safety stock. A company with a product portfolio with a long tail (low-volume products with high demand variability) requires more significant safety stock inventory levels. (Traditional approaches for demand planning as less effective as it becomes more difficult to forecast an item.)
What To Do?
Educate the organization on the basics of inventory and stop using spreadsheets to make supply chain decisions. (Companies using only spreadsheet analysis on cost miss the impacts on inventory of shifts like tax efficiency, outsourcing, or sourcing strategies.)
Use scenario planning in network design optimization and what-if analysis in discrete-event simulation to set inventory levels for each form and function of inventory. Elements of Form and function of inventory Manage Form and Function of Inventory
Analyze the current health of inventories. As companies recover from the past thirty-seven months of disruption, warehouses worldwide are bloated with incorrect inventories. High levels of inventory decrease customer service reliability. (A full warehouse is inefficient, requiring more labor and sophisticated approaches for inventory management. As a result, order reliability drops as inventory levels rise.)
Take the hit—write off slow and obsolete inventories. As you manage the write-offs, analyze the root cause of the inventory write-off as a learning exercise for the organization.
Summary
Traditional methods of focusing on cost management on spreadsheets or using safety stock optimization in supply chain planning must be revised. Train the organization to recognize and manage the form and function of inventory as the organization makes shifts in product complexity, sourcing strategies, and financial tax efficiencies to measure and understand the impact on the form and function of inventory. Manage inventory as an asset. Avoid waste.”
Credit Lora Cecere. Forbes (May, 2023), How Manufacturers Lost the Inventory Battle