Safety-critical real-time systems must comply with stringent certification requirements, including temporal ones. Failure to comply with those temporal requirements may contribute to the system failure. Therefore, timing considerations, such as response times, are of the foremost importance for such systems. As the use of multi-/many-core hardware platforms is becoming inevitable in the avionics industry, due to the increasing computing performance required by modern embedded systems, integration activities are getting more and more complex. Increasing concurrency and parallelism exacerbates integration issues and introduces new challenging problems. To answer those challenges, certification authorities have issued guidelines, referenced as A(M)C 20-193, describing some objectives to fulfill for multi-/many-core integration. The present paper describes how a time-aware approach, based on the Synchronous Logical Execution Time paradigm (sLET), makes the design and integration of A(M)C 20-193 compliant safety-critical multi-/many-core systems easier by separating functional and time interferences concerns.