Software Development Cycle : 1- customer needs : In this phase the customer tells the Embeded system engineer what are the requirements for his product. 2-System engineer: Take these requirements and start to divide it into two ways A) What is the technology to be use (which hardware ) and send the specifications of this hardware to hardware team. B) How to control this hardware throw software. And send Components/System Requirements Specifications ( C/YRS ) to software team to notify that how to control this hardware. 3- Software phase: A) in this phase after taking ( C/YRS) and make analysis to it we can have Software Requirements Specifications ( SRS ) -SRS: functional breakdown Make categories of software and analysis it to tell software engineers what to do ? B) High level Design : (Architect Engineer Role) result of this phase is the answer of How to Do ? Divided into two sections 1) Static design: In this section we will make the layer architecture to this product. And estimate the number of c files, the responsibility of each one and the number of interfaces ( functions) in each file, it's responsibility too. 2) Dynamic Design: In this phase find How to behave at the run time? 4- Detailed Design / component design In this phase generating c files Embeded software engineer role ( coding) 5- Testing Test against c file -> ( component test ) Test against more than c file ( models ) -> ( integration test ) Test against SRS -> ( validation test ) Finally the software cycle can make throw 1) Water fall model 2) V-MODEL 3)AGILE MODEL ( incremental model) You can search for them because they have more details I can't explain it here.