The enterprises active in the industrial subcontracting branch are in a very competitive market and support large pressures on their prices and delivery schedules. The arrival on the market of suppliers from low-cost countries like Eastern Europe or the Far East increases the pressure and drives towards delocalization. One possible answer to these demanding challenges is to cooperate within collaborative networks. Even if this concept is now rather well known, few SME are actually involved in such alliances and their success rate after a couple of years seems low. This paper presents a study of the success and failure factors resulting from the analysis of two collaborative networks of SME in the Swiss subcontracting industry.