An AUTOSAR-based embedded software consists of a set of inter-connected Software Components (SWCs). Each SWC contains a set of runnables which are small code-fragments that should be mapped to Operating System (OS) tasks. This process of mapping runnables to tasks may affect both the system real-time schedulability and performance. This paper proposes fast and efficient algorithms for mapping runnables to tasks. For a given embedded software containing a defined set of runnables, proposed algorithms define the number of required tasks to schedule the set of runnables, tasks priority assignment, and execution order of runnables inside each task. Experimental studies have been carried out to assess the proposed solutions. They outline both the computational efficiency, and the performance of proposed algorithms in comparison with other existing methods.