|Not all Digital Practitioners develop applications. As SaaS options expand, many practitioners will focus on acquiring, configuring, and operating them. However, the premise of this Competency Area is that all Digital Practitioners need to understand at least the basics of modern application delivery in order to effectively manage digital sourcing and operations. Understanding these basics will help the practitioner develop a sense of empathy for their vendors supplying digital services.|
Based on the preceding competencies of digital value understanding and infrastructure, the practitioner can now start building.
IT systems that directly create value for non-technical users may be called “applications”, “digital products”, or sometimes “services” or “service systems”. As discussed in Digital Value, they enable value experiences in areas as diverse as consumer banking, entertainment and hospitality, and personal transportation. In fact, it is difficult to think of any aspect of modern life untouched by applications. (This overall trend is sometimes called Digital Transformation [Westerman 2014].)
Applications are built from software, the development of which is a core concern for any IT-centric product strategy. Software development is a well-established career, and a fast-moving field with new technologies, frameworks, and schools of thought emerging weekly, it seems. This Competency Area will cover applications and the software lifecycle, from requirements through construction, testing, building, and deployment of modern production environments. It also discusses earlier approaches to software development, the rise of the Agile movement, and its current manifestation in the practice of DevOps.
This document uses an engineering definition of “application”. To an electrical engineer, a toaster or a light bulb is an “application” of electricity (hence the term “appliance”). Similarly, a Customer Relationship Management (CRM) system, or a web video on-demand service, are “applications” of the digital infrastructure covered previously.
In the first decades of computing, any significant application of computing power to a new problem typically required its own infrastructure, often designed specifically for the problem. While awareness existed that computers, in theory, could be “general-purpose”, in practice, this was not so easy. Military/aerospace needs differed from corporate information systems, which differed from scientific and technical uses. And major new applications required new compute capacity.
The software and hardware needed to be specified in keeping with requirements, and acquiring it took lengthy negotiations and logistics and installation processes. Such a project from inception to production might take nine months (on the short side) to 18 or more months.
Hardware was dedicated and rarely reused. Servers compatible with one system might have few other applications if they became surplus. In essence, this sort of effort had a strong component of systems engineering, as designing and optimizing the hardware component was a significant portion of the work.
Today, matters are quite different, and yet echoes of the older model persist. As mentioned, any compute workloads are going to incur economic cost. However, capacity is being used more efficiently and can be provisioned on-demand. Currently, it is a significant application indeed that merits its own systems engineering.
|To “provision” in an IT sense means to make the needed resources or services available for a particular purpose or consumer.|
Instead, a variety of mechanisms (as covered in the previous discussion of cloud systems) enable the sharing of compute capacity, the raw material of application development. The fungibility and agility of these mechanisms increase the velocity of creation and evolution of application software. For small and medium-sized applications, the overwhelming trend is to virtualize and run on commodity hardware and OSs. Even 15 years ago, non-trivial websites with database integration would be hosted by internal PaaS clusters at major enterprises (for example, Microsoft® ASP, COM+, and Structured Query Language (SQL) server clusters could be managed as multi-tenant).
The general-purpose capabilities of virtualized public and private cloud today are robust. Assuming the organization has the financial capability to purchase computing capacity in anticipation of use, it can be instantly available when the need surfaces. Systems engineering at the hardware level is more and more independent of the application lifecycle; the trend is towards providing compute as a service, carefully specified in terms of performance, but not particular hardware.
Hardware physically dedicated to a single application is rarer, and even the largest engineered systems are more standardized so that they may one day benefit from cloud approaches. Application Architectures have also become much more powerful. Interfaces (interaction points for applications to exchange information with each other, generally in an automated way) are increasingly standardized. Applications are designed to scale dynamically with the workload and are more stable and reliable than in years past.