Enterprise systems must have the structure to adapt the change of business environment. Whenrebuilding enterprise system to meet the extended operational boundaries, the concept of IT cityplanning is applicable and effective. The aim of this paper is to describe the architectural approachfrom the integrated information infrastructure (In3) standpoint and to propose for applying the “CityPlanning” concept for rebuilding “inter-application spaghetti” enterprise systems. This is mainlybecause the portion of infrastructure has increased with the change of information systems fromcentralized systems to distributed and open systems. As enterprise systems have involvedheterogeneity or architectural black box in them, it may be required the integration framework(meta-architecture) as a discipline based on heterogeneity that can provide comprehensive view of theenterprise systems. This paper proposes “EII Meta-model” as the integration framework that canoptimize the overall enterprise systems from the IT city pl Enterprise systems must have the structure to adapt the change of business environment. Whenrebuilding enterprise system to meet the extended operational boundaries, the concept of IT cityplanning is applicable and effective. The aim of this paper is to describe the architectural approachfrom the integrated information infrastructure ( In3) standpoint and to propose for applying the “CityPlanning ” concept for rebuilding “inter-application spaghetti ” enterprise systems. This is mainlybecause the portion of infrastructure has increased with the change of information systems from centralized systems to distributed and open systems As enterprise systems have involvedheterogeneity or architectural black box in them, it may be required the integration framework (meta-architecture) as a discipline based on heterogeneity that can provide a comprehensive view of theenterprise systems. This paper proposes “EII Meta-model ”as the integration framework that canoptimize the overall enterprise sys tems from the IT city pl