# An Online Multicriteria--Spatial Decision Support System for Public Services Planning
## 3 Requirements and Methodology
### User Requirements of Planning Institutions  
As already mentioned in the introduction, in order to offer a suitable solution for public service planners, a wide range of requirements are placed on data, models, technical analysis, and planning tools (in the form of SDSS) in combination with a well-structured user interface:  
1. Data: Planners and decision makers need an overview of the spatial situation and distribution of population and supply locations, as well as of the transport links between them. This requires small-scale data bases that map the population distribution, reflect the locations but also the utilisation capacities of the infrastructures in question, and allow for analysis of the accessibility, i.e., the connection between the population points and the infrastructure facilities (network data). 2. Complex models: Appropriate models must be used to map the utilisation of the infrastructures and to determine the capacity limits. In addition, the applicable planning regulations, which can also be understood as an influencing factor on models, parameters or criteria, must be considered. 3. Technical analysis and planning tool in the form of a spatial decision support system (SDSS): In order to give a planner a nearly realistic picture of the current situation or a scenario, the planner must be able to set individual parameters from the corresponding specialist domain. The professional preferences of the respective domain are decisive here. 4. User interface: A simple and user-friendly interface is needed to be able to carry out complex analyses and present the results according to preferences. For the development of a system that is intended to support the decisions of regional and state planners, it is necessary to understand the scope of tasks and the type of decisions that should be made. Therefore, several workshops were held to define the decision-making problem. Some of the workshop sessions were conducted with administrative staff from Lower Saxony. Representatives from the offices of regional state development and from the ministries entrusted with state development and planning were present. In order to obtain further important impulses and ideas for application development, another workshop was explicitly aimed at planners who were not part of the Lower Saxony state administration [35]. This resulted in two specifications for the application. On the one hand, we were able to agree on the selection of criteria and the necessary criteria with the help of the workshops and by surveying the participants. We used an interactive mock-up to triangulate the necessary functions and criteria with the users. On the other hand, three key decision-making tasks and problems were identified and integrated into the tool:  
* Supporting the alignment of funding areas and funding allocation: The multi-criteria analysis can support both the identification of priority funding areas and the evaluation of funding applications for various areas of services of general interest. For example, under-supplied villages can be predestined for funding when setting up a community shop because it is possible to make comparative statements about the need and necessity. Another example is the targeted promotion of the establishment of new medical practices in underserved planning areas within small, limited areas (villages). * Review of basic and (partly) centralised provision: The MCDA can support the review and designation of central places. For example, an assessment of the central functions can be made by jointly considering the amenities (including accessibility, etc.). Likewise, localities that fulfil the characteristics of service centres for the population but are not designated as basic or (sub)central places can be identified. * Support in the designation of settlement areas: In the course of increasing land consumption, settlements should be developed with caution.