What is Chain Of Commands(COC)? Chain of command describes how we will extends or customize the Microsoft base code in Dynamics365. we can not perform any customization on Microsoft base objects/standard objects and codes directly. But we can make changes to separately on objects and then those changes can combine with base objects to make final version. Why Microsoft introduced the COC concept? In Ax Dynamics 2012 and earlier versions developers are able to directly modify base Microsoft standard code for any customization and modification. There is a problem by doing direct modification of base code is that when Microsoft releases a hot fix or new features, the modified code need to be remerged with new base code other wise the clients cannot have proper intended purpose of modification the merging is time consuming process. So that Microsoft re-architected the code in such a way the base objects cannot be modified directly. When to use Chain of Commands? Standard Microsoft obje...