Social problems, such unsustainable development, can be too large for any one organization to tackle alone so are increasingly being addressed through cross-sector multi-organizational collaborations. One of the approaches being taken is formulating and implementing a collective (alternatively named collaborative) strategy. Despite the increasing usage of collaborative strategic management in practice, there is relatively little literature on this approach, particularly when considering the implementation of the collaborative strategy. This paper builds on existing interorganizational collaboration theory and organizational strategy implementation theory to determine: 1) a conceptual process model of collaborative strategic management; and 2) factors which affect each phase of cross-sectoral social-oriented collaborative strategic managment.