Family harmony is a key ingredient in bringing about continuity in the family business. To preserve such harmony and good communication the business family is advised to start building a family constitution. Dr. Brahim Allali, Professor at HEC Montreal and Business Family Coach, explains how the degree of communication and the utility of a family constitution are a function of the family generation in charge and describes in a case study how a business family may come to surprising results when embarking on writing a constitution.