The model and frameworkTraditional EA approach prepare transition plan by the whole. For example the Federal Enterprise Architecture framework :
However, the author has encoutered difficulty in several EA project to in planning transition by the whole. Enterprsie architecture is large, and it is unrealistic to conduct gap analysis between existing and target architecture design. A important engineering priciple is to divide and conquer. LEA suggest that :
Target architecture must be planned as a whole but implemented by pieces. It is an effort to divide and conquer the complex target architecture plan based on the LEA framework as shown in the following figure :
The target architecture can be implemented in a segment approch by the four rows and six column in the framework. The OMB segment architecture further detail the categories in the OMB FEA practice guide.