Work-In-Progress is often used interchangeably with Work-In-Process. Conceptually, both terms are similar in that they refer to the costs associated with a partially-finished good or service moving across the production floor. But they can mean different things in specific instances. In general, Work-In-Process inventory refers to partially completed goods that move from raw materials to a finished product within a short time frame. In contrast, Work-In-Progress refers to a production process that requires a longer time frame.