Abstract—Introduction: Surgical instruments are stored, transported, cleaned, disinfected, and sterilized in instrument sets. These instrument sets have a predetermined fixed size, which means they cannot be stored or transported efficiently when empty or used efficiently for different types of instruments. This report presents the design of an instrument set that is adaptable in shape for efficient storage and transport. Method: Based on a questionnaire completed by various departments that come into contact with instrument sets, such as the CSSD, logistics and repair and fixation, the context, the requirements and wishes of van Straten Medical. B.V. and CSA Services B.V., 15 requirements and criteria have been established. Five concepts were developed based on a morphological chart, after which a Harris profile showed that stacki is the best concept. Result: Stacki was further developed and designed using the 3D CAD software SolidWorks. 3 prototypes were created using water/laser cutting and 3D printing. To evaluate the prototypes and identify critical points, 3 tests were carried out regarding completion, ease of use, and strength. These tests have shown that the prototype is promising, but that the corner needs to be redesigned to make the prototype even better. Discussion: Of the requirements, 7 requirements have been met, and 6 requirements were not tested. For further research, these remaining requirements can be tested by applying the points of improvement. Conclusion: A prototype with perforations made from the final materials could be made and this new prototype could be tested for cleaning, disinfection, and sterilization. Finally, the idea with two half sides instead of one long side can also be further developed and tested. Overall, the instrument set is promising for further development, with this design as a starting point.