According to Adam Getz, Program Manager at Excelity, the primary goal of Enterprise Architecture (EA) is to align business and information technology (IT) objectives across the organization. EA enables the process of planning and designing business and IT capabilities across the organization [1]. Getz explains that EA is broken down into four domains or layers: (1) Business, (2) Data, (3) Application, and (4) Technology. The domains (layers) of EA are illustrated in Figure 1.

Every layer of the EA stack is essential and brings important organizational components to light. This blog post will explore the Application Layer and its shift toward modern application architecture. The most basic way to summarize the application layer is the thought of the end-to-end structure of applications. The application layer serves many purposes, from providing an application inventory to support portfolio management to deep diving into architectures such as microservices and data streams [2]. Mike Rose of Technology Transfer says, “The application domain is critical in providing interoperability in support of user experience, in providing flexible services, and managing cost and complexity.” [2].

Application architecture has come a long way in a relatively short time. As a result, modern-day application architecture is shifting in many ways. The first noticeable shift is from monolithic application architectures to modern architectures such as microservices. The second significant shift is the platforms organizations use to host their application architecture, shifting from traditional on-premises applications and supporting infrastructure to Software as a Service (SaaS), Infrastructure as a Service (IaaS), and Platform as a Service (PaaS) offerings.

Traditional application architectures tend to be tightly coupled, monolithic, and complex architectures with large code bases, typically hosted within the organization’s datacenter(s) (on-premises [on-prem]), although not exclusively on-prem. Pictured in Figure 2 (below) is one of the most common architectures you may encounter, a three-tiered stack consisting of web/presentation, application, and database tiers. In these architectures, you will find network infrastructure (firewalls, load balancers, etc.) and server infrastructure (custom-coded or off-the-shelf applications and database back-ends). According to Talend, these systems are designed to handle multiple related tasks. The tightly coupled nature of these systems makes them difficult to manage and update, where an update to a single component of the system could cause an outage of their entire system.

Modern application architecture introduces new technologies and methodologies, such as the Mesh App and Service Architecture (MASA). Gartner Inc. describes the MESA model as providing an evolutionary approach that enables development teams to iteratively and continuously modernize an organization’s applications in direct response to business priorities [4]. The MASA model combines three elementary architectural concepts that support digital business requirements; they are: (1) multi-experience, (2) mediated APIs, and (3) multigrained services. Figure 3 provides an overview of how the three concepts integrate.

The second shift is in the infrastructure that supports the application architecture. Today, many organizations are strategically reducing their data center footprint by using “as a service” solutions such as IaaS, PaaS, and SasS. Utilizing “as a service” offers numerous benefits to an organization, including cost reductions, eliminating the need to purchase and manage hardware, eliminating the need to update software, and increasing system availability. “As a service” platforms are trending in many industries today.

In summary, application architecture is not a new concept to organizations; however, modern application architecture design and delivery are rapidly transforming how organizations design and operate systems and do business today. As a result, the application architecture layer of EA is critical to all Lines of Business within an organization. It plays a significant role in fusing technology infrastructure to conduct business.

References

[1] A. Getz, “Enterprise Architecture – Domains and Pillars,” 16 September 2021. [Online]. Available: https://www.linkedin.com/pulse/enterprise-architecture-domains-pillars-getz-pmp-csm-aws-cmmi/. [Accessed 10 September 2022].

[2] M. Rosen, “Understanding enterprise architecture domains,” January 2021. [Online]. Available: https://technologytransfer.it/understanding-enterprise-architecture-domains/. [Accessed 10 September 2022].

[3] “Three tier architecture: the beginning,” 11 February 2018. [Online]. Available: https://medium.com/coffeetechandme/three-tier-architecture-the-beginning-2d2f6063fa1e. [Accessed 10 September 2022].

[4] “Monolithic vs. Microservices: a guide to application architecture,” [Online]. Available: https://www.talend.com/resources/monolithic-architecture/. [Accessed 10 September 2022].