In the Netherlands the goal of the government is to increase the amount of electricity produced from wind turbines on land to 6000 MW by 2020. This ambitious goal asks for a different approach for these projects, because with the classic approach the development is too slow and invokes too much resistance in the local community. The largest delays during the development of wind parks are caused by problems during the decision-making process. To increase the speed and keep all involved actors on board the decision-making process can be managed by a process manager. Because this is a very complex task, the process manager might need support during the process. Although different models are made that calculate the business case of a wind park, there is no tool available that sees a wind park project as a process in which all important actors are included. Existing models look at a wind park from the eye of the project developer, such as the business case model of Agentschap NL (Veghel, 2013). In this research we will not be looking at one actor, but we will take a multi-actor approach. Only financial aspects are included in the existing models, while the processes are including much more than only financial aspects. In these decision-making projects the influence of the park on the surroundings, the risk of participation options, and the development of the region are only a few of the issues present. Therefore in addition to the multi-actor character of the tool we will include more aspects to the tool than just the financial aspect. The absence of literature describing the causes of the slow progress in decision-making processes of wind-on-land projects in the Netherlands led to the following research question; How can the problematic aspects during the decision-making process of wind-on-land projects be managed? To answer this question we have to identify the problematic aspects, the requirements of good process management and the products of decision-making. After that we can look to the tool and therefore the following design question was developed; How can a process-support tool help the decision-making process of wind-on-land processes? To answer the research question we reviewed literature, conducted expert interviews and analyzed the cases of Deil, Houten, Dronten en Nijmegen. The Deil case has been extensively analyzed, because we participated in the process of decision-making in multiple rounds. To review the prototype of the tool we interviewed the actors involved in wind park Deil, including the two process managers. This gave us the input for revising and adding aspects of the tool. The Decision-Making Processes The slow progress of this decision-making process is caused by the lack of trust among the actors, the lack of available information of the actors and the different languages the actors speak. The negotiation rounds during this process are taking a lot of time, because, due to the problems mentioned, actors are not able to decide on the complex aspects of the three products of decision-making, namely; the municipal spatial plan, the business cases and the participation plan for civilians. These three products are linked in multiple ways, although these links are not known by all actors. Choices for one product affect the other products and in that way change the project. The tool shows what the effects of these choices on the project are, so the actors can see what their proposals do for the project. The WINST The designing phase of the thesis led to the WINST (Wind In Nederland Support Tool) in Excel based on the Agentschap NL model of (Veghel, 2013). Two additions were done to this model. First, all important actors were included; the project developer, the municipality, the province and the civilians. The existing model calculated the business case for the project developer and partly for the municipality, but neglected the civilians and the province involved. Moreover, the other goals except for the business case were added to the tool. A positive business case is just one of the goals of an actor and, as we wanted to include more than just financial aspects, we included the other goals per actor. This led to additional sheets to the existing model with a multi-criteria table for each actor is shown in which the criteria are the goals of the actor. The weights and scores in this multi-criteria table have to be given by the actors using the input provided partly by the existing model and partly by new input sheets, covering the spatial plan and the participation plan. In the tool the effects of different proposed options are clearly listed per goal, so the actor can assess the option based on the key variables. For the process manager an overview sheet was added, so the tool can easily be presented during the negotiation rounds. Usability of the WINST To test the preliminary assumption that the WINST could help during the decision-making process all actors involved in wind park Deil were interviewed, including the two process managers. These interviewees all stated that the WINST could help in the process by informing the inexperienced actors and checking proposals on their feasibility. The actors all saw the WINST being used at the earliest stages of the process, so the inexperienced actors could really participate in the discussion from the start. This helps to distribute the information among the actors. It can also increase the trust as the discussion about the goals of the different actors can create more clarity about the motives of the actors and in that way bring actors closer. At last the tool can help the actors to ask the right questions during the negotiation rounds and form a jargon with the tool as the basis for all actors. This can decrease the differences in languages among the actors. The WINST has become a large Excel file, which is not easily used by a process manager without a lot of knowledge about wind parks, as was remarked by the process managers during the interviews. Therefore we added a user guide to this thesis, in which the process manager will be led through the tool in several steps. The process manager will have to sit down with each actor separately to explain the tool and collect the weights and scores to reduce the chance on strategic behavior. Future works Before the tool is used in a real process, one improvement has to be made. A thorough verification and validation of the tool has to be conducted. Now we only roughly analyzed the outcomes of the tool by entering the default settings of the Agentschap NL model. In that way we could estimate during the development of the tool in an iterative process if the tool was producing values that were reasonable. Before the tool is used all factors and links have to be checked for accuracy and the tool as a whole should be checked for producing values and scores that are reasonable. In this check also a sensitivity analysis should be conducted to see if the tool is very sensitive for the input of certain variables. With the improvement mentioned above the tool could be used by a process manager, but further improvements can improve the usefulness of the tool even more. First, the tool can be expanded by adding more variables and links to make the tool more complete. In section 4.5 linked variables that were too complex were left out of the tool, but a separate study can try to incorporate these links. Second, a thorough guideline for the tool can be written. Although a user guide is comes with the report, a more thorough guideline can help clarifying the following points; when to use the tool and when not to use the tool, what can be negative effects of the tool, how can these negative effects be overcome, what can be strategic behavior and how can this be decreased? Third, a process (with place for the tool) can be designed. A process design from start to finish of the process can help as guidance for the process manager.