A good team can make or break the success of a project. Where does this success come from? Is it the way of cooperation or is it the mixture of the right personality types in a team? Do you pick the right personalities and make them work together or does it happen naturally? Different personality types contribute to a successful team. Although behavior can differ from a personality, it forms a base of behavior people feel comfortable with. Knowing your personality type can help you understand what makes you tick. This self-awareness is an important factor in being successful. In general a personality type will define 1) your flow of energy, 2) how you take in information, 3) how you prefer to make decisions, 4) the basic day-to-day lifestyle that you prefer. Many methods can help discover personality types. Myers-Briggs type indicator, (i)DISC assessment, Enneagram of personality, etc. supply tests in order to figure out what personality type people have. Some of these methods need intensive testing, and are therefore hard to apply without doing the actual test. However some of the elements of a type can be noticed without intensive testing. For instance the way people get their energy. Do they get their energy from within themselves or from external sources? Do they absorb information in principles or in details? Are they comfortable with scheduled/structured or open/casual environments? Knowing these preferences it will be easier to approach and work with other person. In a team people often differ, but are these differences always bad? Some people see these differences as a flaw that needs to be corrected. However the personality type (or character) cannot be changed, so why bother? And even if you can change the personality type of a person does it help the project? Having only one type in a team will slow down the project. For instance, a team full of inspirers will hardly finish anything. After creating an idea they will get bored long before the project is finished. Different personality types in a team can complement each other and create a successful team. Having a team with different personality types will probably result in a project failure if the people approach each other in the way they feel comfortable. For instance an intuitive person can handle fuzzy data (for instance, the entrance is located at the north side of the building) whereas sensing persons need concrete data (for instance after 50m you take a turn of 90 degrees and after 10m you will find the entrance of the building). Knowing team members’ personality type means knowing strengths, weaknesses and the way of approaching each other. When taking this into account a team is more effective. Working together in a team will normally go through the following stages: 1) Forming, 2) Storming, 3) Norming, 4) Performing, 5) Adjourning. In relation to the personality types, the norming stage is important. In this stage expectations, styles, roles, etc. are set. During this stage strengths and weaknesses need to be discovered in order to prevent conflicts or hurt feelings. Listening and understanding the team members can help to support and complement each other. In conclusion a personality-type does matter! It will help to understand what makes you tick. This self-awareness is the key to being successful. However a personality type indicates preferences and does not indicate the strength of ability of a person. Knowing these preferences it will help understanding other team members and work in a more effective way.