There's a default behavior in almost every inventory planning system that almost nobody talks about during onboarding: spare parts, accessories, and components that aren't primary catalog items default to inactive status. They don't show up in your main demand planning view. They don't trigger reorder alerts. The system isn't tracking them.
They are, however, selling. Quietly, every month. And running out.
This is exactly what happened with Samako.
What Inventory Planner does with inactive items
Samako runs an import and distribution operation with container-based supply chain management. When we built out their master forecasting sheet and connected it to demand planning, we ran an audit of what was actually being tracked.
The spare parts category was marked inactive in Inventory Planner. Inactive means excluded from demand forecasting, excluded from reorder point calculations, and excluded from the alerts that would tell you when stock is getting low. From the system's perspective, those items don't exist as things that need managing.
From a customer's perspective, they absolutely exist. When a product needs a replacement part, that part needs to be available. When it isn't, it's a customer service failure. In some categories it can also be a sale of the main product that doesn't happen, because the customer who had a bad parts experience doesn't buy the next version.
The items were being sold and depleted. The replenishment decisions weren't being made because there was no alert to prompt them. The system was doing exactly what it was configured to do: ignoring inactive items.
The fix was one setting change
Changing the status from inactive to active in Inventory Planner immediately brought those SKUs into the demand planning view. They started generating forecasts based on historical sales. Reorder points got calculated. Alerts started firing.
That's it. One setting change. But the underlying issue isn't Samako-specific, and the fix isn't the interesting part of the story.
The interesting part is how common this is and how reliably it gets missed.
Why it gets missed every time
Onboarding to a demand planning tool follows a predictable pattern. You connect your data sources, you configure your main catalog, you set lead times and safety stock parameters for your primary SKUs, and you review the outputs. The whole session is oriented around the products you think of as your products — the ones with real revenue lines, the ones you actively manage.
Spare parts and accessories are an afterthought in that process. They often weren't set up in the planning tool to begin with, or they were set up at some point and then marked inactive because someone was cleaning up the item list and didn't think carefully about the downstream effect. Nobody mentions them during onboarding because they're not part of how anyone thinks about the catalog.
The problem is that any item marked inactive is invisible to the planning system. And invisible items in demand planning tools have a predictable outcome: they run out without warning.
What the audit should look like
Every onboarding to a new demand planning tool needs an explicit exclusion audit before the configuration is considered complete. The question is not "does this tool have the right items?" It's "what does this tool not see?"
Pull a list of every SKU in your catalog, including accessories, replacement parts, bundled components, and any item classified as non-primary. Compare that to what's active in the demand planning tool. The gap between those two lists is your exposure.
At Samako, the gap was in spare parts. At other clients it might be in accessories, in bundles, or in promotional items that were temporarily deactivated during a sale and never reactivated. The specific category doesn't matter. The principle is the same: whatever the tool isn't seeing, it can't manage.
The audit takes an hour. The alternative is discovering the gap when a customer asks for a spare part you haven't stocked in three months because nothing was telling you to.
A broader point about tool configuration
Inventory planning tools are only as good as what they're configured to see. This sounds obvious when stated directly. In practice, it gets lost in every implementation because implementations focus on what the tool can do, not what it's currently ignoring.
Set items active. Review exclusion lists. Check default statuses for every category. These are the boring steps in a tool configuration that save you from the frustrating conversation six months later about why a category keeps running out when you have a demand planning tool specifically designed to prevent that.
