475 The technical requirements were derived from customer feedback and performance parameter evaluation.  In brief , the main  targeted improvements (compared with SARA21)  were :  1. Higher torsional stiffness   2. Higher detent torque   3. Smaller step size   4. Same or smaller mass and dimensions   In the beginning,  the requirements were limited to the top- level requirements and the first concept was  based on these  top-level requirement s. Then key  suppliers were selected and the concept was iteratively  refined together with the key  suppliers.  This allowed the suppliers to offer , without interface limitations, the  best possible product for the application. Based on this configuration the requirements were revised and  further broken down. From this moment the requirements  got a weight ing factor which was used to give  priorities in case of conflic ts. This way of requirements definition  supported with weight ing factors allowed  a straightforward optimization of the concept.  

Demonstrator Definition  Soon  it became clear that the project w ould result in an advanced product which has two main  technological   elements :  a compact gear stage with a high gear ratio and a  robust and contactless position sensor. Both  technologies were new and their performance could not be defined and analyzed accurately enough .  Therefore, the only possibility was to test the technologies in order to assess whether they comply with the  requirements. For this, i t was decided to build a breadboard model  that would allow the determination of  the performance parameters. T his technology demonstrator was called the Future Actuator.  The  breadboard model , compared to a qualification model or other advanced model s allow ed a quick and  simplified development and testing  cycle . This was exactly what was  needed to evaluate the compatibility  of the selected technologies with  the next generation of rotary actuator s. It was decided to build the  breadboard as close as possible to the anticipated final configuration  to ensure a reliable performance data  under all environmental conditions . The breadboard was  split in two areas :  the gearbox  with the main  bearing and position sensor and the motor. With this modular arrangement,  the motor is independent from  the gearbox . The modularity of the motor is a feature that has two main advantages :  one is that the motor  can be select ed based on the tested performance;  the second is that the motor c ould be easily exchanged ,  which allows the customer to exchange the motor with minimum impact  to the overall product , if needed . 

Development at RUAG  

The Future Actuator development was a kind of experiment to test some development aspects that  were  not used before at RUAG . One aspect of the development was the team size. The team was very small  and having such a small team had  the advantage of quick decisions and iterations. The disadvantage was  the lack of collaborative inputs, which  had to be compensated. In RUAG , all employees are located close  to each other , which allows access to the needed know -how very easi ly. This circumstance was intensively  used and all the experts were consulted constantly in order to ensure the maximum benefit from internal  know -how. The decision process was very short which allowed a quick definition of the concept.  

Design Thinking   The development approach used for the Future Actuator  was very much in line with the design thinking   approach. The design thinking approach aims at open- minded development of product s with higher  complexity. There are different interpretations of the design thinking.   At RUAG,  the design thinking approach is understood as follows :  1. Identify and understand the need (requirements)   2. Create different solutions  and s elect the best concept   3. Get inter -disciplinary inputs to refine the concept   4. Test early and be flexible in this phase   5. Improve the product based on test results and updated  customer  requirements