In recent years, the non-conventional generation sources (i.e., wind, PV, and others) have emerged as excellent alternatives for the traditional synchronous machine for power generation. It is also reported that the socalled system strength may be reduced with high penetration of non-conventional generations (NCGs). A number of methods are used to assess the system strength which may not reflect the interdependency or interactions among various factors affecting system strength. This paper presents a thorough assessment to quantify the implication and interaction of various factors affecting the system strength, where the voltage recovery index has been used as a quantification tool.