Engineering Critical Assessment (ECA) procedure, which is a method to evaluate the integrity of various structures with embedded crack, surface crack and multiple cracks and so on. In BS7910, the acceptability of flaws in metallic structures is typically dealt with in terms of stress intensity factor solution. For the case with more than two flaws, BS7910 provides various flaw interaction rules. While such flaw interaction rules are developed based on many parametric studies, it is generally known to lead to very conservative results. In this study, the stress intensity factor solutions in a plate with multiple cracks are evaluated. Target structure is a simple plate subjected to tensile and bending loads, and a series of finite element analysis is carried out using ABAQUS. In addition, the results are validated against previous studies available in literatures. Based on the study, the distance criteria for multiple cracks in PD6493 and BS 7910 are found to be overly conservative. Therefore, a parametric investigation regarding the distance between multiple cracks is examined to reduce the overly conservative estimation in existing standards.