# Agile Stage-Gate Approach for Design, Integration, and Testing of a 1U CubeSat
## 2 Materials and Methods
### Agile Stage-Gate Methodology  
As noted, many industries employ traditional Stage-Gate approaches. The development of the AztechSat-1 nanosatellite using the proposed model combines Agile ideologies, such as using one room and daily meetings, with stages that provide a guide for the recommended activities. Iterations enable feedback and give opportunities to review and plan new perspectives. The AztechSat-1 Agile Stage-Gate model is shown in Figure 3.  
The AztechSat-1 process started with a small task force composed of professors and a medium task force of students from different backgrounds involved in product design and process development. The team also employed external experts (NASA and AEM  
Figure 3: AztechSat-1 Agile Stage-Gate hybrid model. engineers). From the beginning, while working on the Agile method, all members of the team dissected the existing stages. The first step was to streamline the process. To make the requirements less troublesome, UPAEP organized different teams for each subsystem; then, a training program was created for participants interested in working on the project with the goal of evaluating their skills and reducing cycle time before moving to the hybrid model. In each phase of the Stage-Gate method, project leaders determined where Agile would work. A pilot test for planning and working on the model was established with some members of the project. After the results of this pilot test were confirmed, the whole project was moved to work on this project. Before this project, the AztechSat-1 team had no previous experience, so everyone learned how to proceed during the course of the work. The learning process at some points seemed to be impeded, producing a sense of frustration. However, external coaching was efficient and, as a result, coaching and open dialogue became the de fact standard. AztechSat-1's design, integration, and testing went through an iterative and recursive process. The advantage of following a cycle in each of the stages allowed the team to detect as many failures and errors as possible in the early stages so that changes could be solved, starting from the most basic level with the lowest impact. The Agile Stage-Gate hybrid model focuses on customer requirements or needs and incorporates sprints from other methodologies. Sprints are held in short time intervals (AztechSat-1 project sprints were executed every one to four weeks). For our grounded theory, the case study method was chosen because it allowed respondents to describe their perspectives with flexibility. Three levels were leveraged: identification of concepts, iterative analysis and testing, and integration for validation and verification. Figure 4 illustrates the iterative and recursive strategy for the conceptualization, design, integration, testing, and transition (post-launch events) of the AztechSat-1 nanosatellite adapted from Wells [21]. Figure 3 highlights the importance of having a heartbeat for the project. Such a heartbeat requires inputs like those in any other system in which unfinished features or feedback need to be implemented or finished. Most of the aerospace project will present numerous features, but only the most important features need to be considered. Once activities have been determined, daily iterations though planning and improvements will consistently improve. Team empowerment and post-sprint reviews create a responsive heartbeat. This framework needs to be implemented in every stage of the project. The methodology for the Agile development of space hardware and corresponding opportunities have also been identified in the development processes of nanosatellites. Preliminary results have indicated this method's effectiveness, but none of these previous studies presented a hybrid proposal [22]. This hybrid model allows the Stage-Gate process to be integrated with the Agile methodology. Some of the biggest benefits of this model are its speed of product release,  
Figure 4: Framework of the AztechSat-1 Agile Stage-Gate hybrid model adapted from Wells.