Service parts inventory planning and management are provided for one or more entities in a supply chain (12), preferably within the context of an electronic marketplace (14). Status data reflecting substantially current service parts inventory levels at stocking locations within the supply chain (12) is accessed, these inventory levels indicating service parts excesses or needs at one or more stocking locations. A substantially current service parts inventory plan is generated according to the status data, a service parts demand forecast, and a supply chain model, the inventory plan including target stocking levels for service parts at stocking locations. According to the inventory plan, one or more services are initiated to attempt to resolve service parts excesses or needs at stocking locations through interaction with one or more other entities.