Resumen del autor, extraído del trabajo. This article offers practical insights into the creation and development of strategic alliances. Based on the true story of a facilities engineering alliance, the article provides executives and managers with greater understanding of what it can take to create a successful strategic alliance. It also offers reflections on what to consider and the pitfalls to avoid when creating or operating an alliance between two or more companies. The article has three main sections. The first part looks at alliancing in general and then delves into the generally accepted requirements of business strategic alliances. From that context, the second part tells the trials and tribulations experienced by the EXCEL Alliance between Petro-Canada Oil & Gas and the Colt Engineering Corporation. It describes the three evolutionary stages the alliance has gone through for its 3 years of existence. The learnings from each stage are articulated, as well as the action involved in getting EXCEL to its next higher stage of development. The final part of the article summarizes what has been learned from the EXCEL experience. The article reveals that there are no "textbook" answers to the creation and development of a strategic alliance. Rather, it requires ongoing critical thinking by the alliance management, combined with initiative and risk taking. The case study also shows that the successful establishment of an alliance requires the support of both parent companies' senior management, who must be committed to persevering through the growing pains and trials that the alliance encounters. The article's conclusions contribute to the formulation of practical principles to be followed for alliancing.