AvSIL is an affordable, flexible system integration solution for real-time, closed-loop control systems verification and validation, with simulations or hardware-in-the-loop. AvSIL features a modular I/O system enabling connections to common domain sensors and systems found in Environmental Controllers, Landing Gear Controllers, and other avionics systems. With software configurable I/O, AvSIL can quickly be adjusted to the needs of a changing program. It can also be easily repurposed for use across disparate programs reducing NRE costs. AvSIL uses leading edge hardware, a modular design, and powerful automation tools to become a scalable, adaptable, and reusable simulation platform.