Real time embedded systems (RTES) know a growing complexity due to modern applications requirements and architectures complexity especially with the addition of the multiprocessor feature. They are equally subject to a variety of constraints due to their mobility. They need to react to environment variability, resource limitations and timing constraints. An emergent solution to deal with this complexity is the integration of adaptation strategies in embedded systems design flow. The design space of multi-layer adaptation decisions is becoming increasingly vast and difficult to explore. Development of such systems at low system levels is therefore increasingly tedious especially with the limitations of computer aided design tools. Using MDE approach and the UML/MARTE profile for high abstraction level design is becoming a promising solution to ease the design of RTES. In the present paper we recall and classify existing works built around adaptive embedded systems. We concentrate on a set of criteria to help highlighting the shortages of existing approaches on modern adaptive RTES design. We focus on the design environment, adaptation features, online time constraints verification and performance assessment. Finally, we present our future works to cope with the limits of existing solutions while taking into account the observed criteria.