How can a project manager adapt the project plan for an innovation project to the context? This question leads to other matters, such as why is it important for a project leader to adapt the project plan to the context? Firstly, suppose a firm in a market and the executives of the company plan to grow the organization through innovation projects. Then, the executives need to select the project leader based on the personality of the project manager candidates because the project manager’s personalities influence the project success (Müller & Turner, 2007). This step indicates the necessity of analyzing the personality of the project manager candidates. Subsequently, the project manager must create a project plan. In drafting the project plan, the project manager needs to make several decisions depending upon the context because nowadays, firms need to adjust their business decisions depending on contextual factors (Ortt & Van der Duin, 2008). Thus, this step indicates the importance of adapting the project plan to the context. Nevertheless, those practical problems are not resolved yet because no literature connects between the decisions in making a project plan, the contextual factors, and the project leader’s personalities. Literature reviews and experiments are conducted in this study. Firstly, the literature reviews summarize the theory explaining the decisions in making a project plan, the contextual factors, and the project leader’s personalities as well as generate some hypotheses. Secondly, the experiment, aiming to test the hypotheses, asks the TPM TU Delft student to fill out the questionnaires. Then, the 162 valid data were analyzed to form three groups of variables: (a) project plan variables, comprising 37 variables; (b) contextual factor variables, encompassing 2 variables; and (c) project leader’s personality variables, entailing 29 variables. Furthermore, the relationships between the project plan variables and the contextual factors are investigated using analysis of variances. Next, the relationships between the project plan variables and the project leader’s personalities are examined using regression. Lastly, the relationships between the project plan variables and the contextual factors controlling for the project manager’s personalities are analyzed using analysis of covariances. The results show that two contextual factors have influences on the decisions in making a project plan. Likewise, two out of three project leader’s personality variables have effects on the decisions in creating a project plan and moderate the connection between the contextual factors and the decisions in making a project plan. This study has both scientific relevance and practical relevance. In scientific relevance, this study provides newly developed scale measuring the decisions in making a project plan. Likewise, this research brings up the application of the contextual factors theory to the project management as well as the application of the people’s personality theories to the project management. On the other hand, in managerial practice, this research can be a guidance for the executives to appoint a project manager based on the personalities of the project manager candidates and for the appointed project manager to create a project plan depending on the contextual factors.