Current business models base their activities on the manufacturing, distribution and selling of industrial products with a single use phase. But now, products with multiple use phases have to be considered regarding new economic and environmental pressures. Therefore, the related complex life cycles of (re)manufactured products have to be modelled and assessed by design teams for a better understanding of their overall performance. This paper focuses on the remanufacturing strategy. The study shows how to establish environmental assessments for remanufactured products life cycles and how to compare them to environmental assessments for "classical" life cycles. The final objective is to provide easy-to-use methods and tools for designers to allow them to quantify the environmental benefits related to the use of a closed loop strategy. The approach is illustrated by a case study from the industry: the truck injector.