## 4 Development Phase According to Design Science Research  
As mentioned above, the DSR approach is characterized by an initial problem statement. The problem statement here has evolved through a literature screening and process analysis of the involved industry partner. To understand the potential improvement measures in this CtO container service environment, it is important to understand how the containers dealt with can be principally composed and configured with respect to customer demand: The containers are categorized into different typologies (BM10\({}^{\prime}\), BM16\({}^{\prime}\), BM20\({}^{\prime}\), BM24\({}^{\prime}\), and BM30\({}^{\prime}\)) varying in size. The typology denominations refer to the length of the longitudinal side in the unit of feet. Furthermore, the containers are modular components whose external walls are composed of panels with equal geometric dimensions. The longer the longitudinal side, the more panels can be placed there (panel slots). The short side (NORTH + SOUTH) of all container types always has two panel slots (Figure 3). The panels themselves are subdivided into five types differentiated by their functions: (1) full panel, (2) window panel, (3) sanitary window panel, (4) glazed door panel, and (5) door panel. This means that, depending on its longitudinal dimension, a container can have **n** panels on the longitudinal side and exactly two panels on the short side. For unambiguous identification, we have classified the possible panel positions by their sky orientation and sequence (Figure 3). The single panels can be modified arbitrarily according to the customer's requirements to form various types of container facilities such as e.g., temporary schools or construction site offices. At the time of our investigations, the main internal processes of the industry partner whose core business is to plan and install container facilities as rental properties were essentially characterized by (1) requirement analysis of customer demand regarding the container facilities to be erected; (2) translation of these requirements into 2D floor plans using computer-aided design (CAD) software; (3) physical lookup in the local container warehouse to identify which currently present container corresponds the most to the drawing, and hence requires the least modification effort; (4) manual entry of the container's rental ID number of the containers selected onto the floor plan printout (Figure 4); (5) manual transfer of rental ID from printout to CAD software; (6) estimation of modification effort of selected containers with respect to the drawing based on experience; (7) making bid to customer. Figure 5 shows the simplified process from customer inquiry to contract award. Figure 3: General container and panel layout. In addition, the involved industry partner maintained a sort of 2D plan repository of PDF plans for every container in its current configuration. As a consequence, after panel modification for the current project, every 2D plan with respect to both floor plans and views had to be updated manually by means of CAD, which the industry partner considered very time consuming. Considering the above, the identified potentials for improvement can be stated as:  
* Manually maintained 2D drawing repository, which is not linked to the container warehouse
* No documentation about the current container warehouse inventory
* Container assignment (= assigning rental ID to drawing) requires an employee to physically inspect the warehouse
* Effort for panel modifications is estimated based on experience
* Rental IDs are entered manually on 2D plan printouts. The following actions are derived from these improvement potentials:  
* Development of a virtual container warehouse that represents the current availability of the physical containers  
Figure 4: Manual assignment of rental IDs. Figure 5: Current overall process.