As systems become more and more complex, more complex processes, organization and division of work are needed to achieve their conception and realization. The growing difficulty consists in the number and distribution of collaborators in disparate regions on the globe, the multifaceted communities that need to be coordinated in order to assure integration and coherence of their work. It is also the case of building railway technical solutions.The heterogeneity of customer market adds a supplementary challenge: adapt the solution to the customer background, context and real needs. In this context we propose a workspace to support collaboration when building customer technical solutions. We think that adequate collaboration support needs to be provided for each community and that a common backbone is needed between these communities to assure integration and coherence of their work. This paper gives a model and implementation of a dedicated workspace that can handle collaboration during complex processes like the construction of a railway technical solution.