The fundamental elements of media workflows
Mar 1, 2009 12:00 PM, By Al Kovalick
Figure 1. The essential elements of media workflows
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Since the advent of file-based technologies, innovative and powerful implementation strategies are being used for broadcast, news, post and digital intermediate (DI) workflows. This article covers four key features of these workflows: system design considerations, process orchestration, operational aspects and workflow agility factors. Several fundamental flow models have been developed that are components in other more elaborate systems. These include high availability concepts, documenting workflow using unified modeling language (UML) diagrams, file transfer advantages, loosely coupled design ideas, service-oriented architecture (SOA) integration and more.
Key elements of media workflows
Workflows are found everywhere in life. Basically, workflow is defined as “a set of sequential steps needed to complete a job.” Some workflows are easy to implement, needing only a few tools, whereas others demand mountains of infrastructure and human capital.
Figure 1 shows the five precincts of interest for media workflows. The central box represents the actual workflow steps. The other four domains help define the “what and how” of workflow functionality. Some of these are common to all workflows, such as operational elements, whereas others, such as audiovisual streams and file-related processes, are specific to media systems.
Figure 2. Fundamental relationships — A/V and IT systems domain
For the media enterprise, almost agnostic to size, A/V processes are often implemented using a combination of traditional A/V plus IT gear and processes. (See Figure 2.) These hybrid systems support various workflows. Ideally, the implementation is malleable and can morph to meet the needs of future workflow changes. Also, built-in reconfigurability is vital.
Throughout this article, the constituent elements of Figure 1 will be explored with examples. The end goal is to provide a simple, high-level checklist to refer to when building a new workflow or modifying an existing one. This coverage is not exhaustive; not every aspect will be examined. However, you will be versed in the language and concepts of media flows and their design.
The design element
Any viable workflow needs a design stage. The key elements of interest are:
- Architecture
What solution space do you need? - Reliability/scale
There are 14 methods for building reliable systems. - Standards and interoperability
For example, SMPTE, IETF, IEEE, ITU-T, W3C and AMWA. - Implementation
This includes choice of vendors, systems integrator and support. - Documentation
Workflow design is not just wiring and layout.
The famed Chicago skyscraper architect Louis Sullivan said, “form follows function.” This simple yet powerful axiom applies to media workflows as well as skyscraper design. In essence, define your work space, and design it. Allow for growth, support agility and high availability as budget permits, and document not only layout and wiring but flows too. Figure 3 on page 51 shows a typical generic flow for program production. This could be modified for broadcast, live event production, news, DI, or any number of flows.
Figure 3. Generic program creation process flow
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Figure 3 may be the first step in defining the work space for a new project. The level of detail is intentionally high. The design architecture will support these functions at a minimum. As the designer applies the divide and conquer rule, each process is implemented with the end goals in mind of one unified infrastructure, not islands of operations. Any given process may connect to central storage, application servers, a LAN/WAN, or traditional A/V router.
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