The Atacama Large Millimeter /sub-millimeter Array (ALMA) has been working in operations phase regime since 2013. The transition to the operations phase has changed the priorities within the observatory, in which, most of the available time will be dedicated to science observations at the expense of technical time required for testing newer version of ALMA software. Therefore, a process to design and implement a new simulation environment, which must be comparable - or at least- be representative of the production environment was started in 2017. Concepts of model in the loop and hardware in the loop were explored. In this paper we review and present the experiences gained and lessons learned during the design and implementation of the new simulation environment.