It is wise to have a joint venture agreement (JVA) drawn up even if you are collaborating with family members. Misunderstandings are just as likely to occur in that situation as they are if you were working with people you do not know. Also, anyone´s circumstances can change leaving them unable to continue as planned. A decent JVA will cover most circumstances and make it clear what is to be done, thus avoiding a protracted argument with family members.