Regarding to the resource allocation and partition starting time in the Integrated Modular Avionics (IMA), a Unified Modeling Language (UML) model of partition configuration and initialization was proposed based on the case study of VxWorks 653 partition operating system. The proposed model including classes diagram and initial sequence diagram for partition, was established to facilitate the analysis of the mechanism of partition configuration and starting/initialization. The contents and function of partition configuration in the processes of resources allocation, operating system compilation and partition initialization, were discussed in detail, as well as the differences between "cold start" and "warm start" mode. A platform was set up for testing the startup times of the two kinds of startup modes, and the test results showed that the time of cold start was 148 ms, and warm start time was 8.5 ms. Furthermore, the applicable scenarios for cold start and warm start mode were discussed. The policies of partition configuration and application software initialization were proposed based on the starting time. The mode of partition start and time of partition initialization should be fully considered when establishing the partition main time frame and identifying the health management policy. The designed policies can be applicable to other partition system design in high security applications.