Workflow

A workflow is a depiction of a sequence of operations, declared as work of a person, a group of persons, an organization of staff, or one or more simple or complex mechanisms. Workflow may be seen as any abstraction of real work, segregated in workshare, work split or other types of ordering. For control purposes, workflow may be a view on real work under a chosen aspect, thus serving as a virtual representation of actual work. The flow being described often refers to a document that is being transferred from one step to another.

A workflow is a model to represent real work for further assessment, e.g., for describing a reliably repeatable sequence of operations. More abstractly, a workflow is a pattern of activity enabled by a systematic organization of resources, defined roles and mass, energy and information flows, into a work process that can be documented and learned. Workflows are designed to achieve processing intents of some sort, such as physical transformation, service provision, or information processing.

Workflow concepts are closely related to other concepts used to describe organizational structure, such as silos, functions, teams, projects, policies and hierarchies. Workflows may be viewed as one primitive building block of organizations. The relationships among these concepts are described later in this entry.

The term workflow is used in computer programming to capture and develop human-to-machine interaction. Workflow (management) software aims to provide end users with an easier way to orchestrate or describe complex processing of data in a visual form, much like flow charts but without the need to understand computers or programming.

Related concepts
The concept of workflow is closely related to several other fields in operations research and other fields that study the nature of work, either quantitatively or qualitatively, such as artificial intelligence (in particular, the sub-discipline of AI planning) and ethnography. The term workflow is more commonly used in particular industries, such as printing, and professional domains, where it may have particular specialized meanings.


 * 1) Processes: A process is a more specific notion than workflow, and can apply to physical or biological processes, for instance. In the context of concepts surrounding work, a process may be distinguished from a workflow by the fact that it has well-defined inputs, outputs and purposes, while the notion of workflow may apply more generally to any systematic pattern of activity (such as all processes occurring in a machine shop).
 * 2) Planning and scheduling: A plan is a description of the logically necessary, partially-ordered set of activities required to accomplish a specific goal given certain starting conditions. A plan, when augmented with a schedule and resource allocation calculations, completely defines a particular instance of systematic processing in pursuit of a goal. A workflow may be viewed as  an (often optimal or near-optimal) realization of the mechanisms required to repeatedly execute the same plan.
 * 3) Flow control is a control concept applied to workflows to divert from static control concepts applied to stock, that simply managed the buffers of material or orders, to a more dynamic concept of control, that manages the flow speed and flow volumes in motion and in process. Such orientation to dynamic aspects is the basic foundation to prepare for more advanced job shop controls, as just-in-time or just-in-sequence.
 * 4) In transit visibility is a monitoring concept that applies to transported material as well as to work in process or work in progress, i.e., workflows.

Historical development
In the 1980s, the term workflow was first used in its modern form in the software industry by FileNet vice president David Siegel. The company called its business process automation software "WorkFlo".

In 1995, the publishing industry studied how traditional publishing processes could be re-engineered and streamlined into digital processes in order to reduce lagtime, as well as substantial printing and shipping costs for delivering print copies of books and journals to warehouses and subscribers. The term electronic workflow was used to describe the publishing process, from online delivery of digital manuscripts to the posting of content on the web for online access.

The development of the concept of workflow occurred over a series of loosely defined, overlapping, eras.

Beginnings in manufacturing
The modern history of workflows can be traced to F. W. Taylor and H. Gantt. Together they launched the study of the deliberate, rational organization of work in the context of manufacturing. The types of workflow of concern to Taylor and his contemporaries primarily involved mass and energy flows. These were studied and improved using time and motion studies. While the assembly line remains the most famous example of a workflow from this era, the early thinking around work was far more sophisticated than is commonly understood. The notion of flow was more than a sequential breakdown of processing. The common conceptual models of modern operations research, including flow shops, job shops, and queuing systems, can be found in early forms in early 20th century industry.

Information based workflows began to grow during this era, although the concept of an information flow lacked flexibility. A particularly influential figure was Melvil Dewey (inventor of the eponymous Dewey Decimal System), who was responsible for the development of the hanging file folder. This era is thus identified with the simplest notions of workflow optimization: throughput and resource utilization.

The cultural impact of workflow optimization during this era can be understood through films such as Chaplin's classic Modern Times. These concepts did not stay confined to the shop floor. One magazine invited housewives to puzzle over the fastest way to toast three slices of bread on a one-side, two-slice grill. The book Cheaper by the Dozen introduced the emerging concepts to the context of family life.

Maturation and growth
The invention of the typewriter and the copier helped spread the study of the rational organization of labor from the manufacturing shop floor to the office. Filing systems and other sophisticated systems for managing physical information flows evolved. Two events provided a huge impetus to the development of formalized information workflows. First, the field of optimization theory matured and developed mathematical optimization techniques. Second, World War II and the Apollo program were unprecedented in their demands for the rational organization of work.

The classic management tome The Organization Man culturally captured the nature of work in this era.

Quality era
During the 1980s two aspects of workflow organization drew heavy criticism. First, the methods pioneered by Taylor modeled humans as simple automatons. The classical industrial-style organization of work was critiqued as being both dehumanizing and suboptimal in its use of the potential of human beings. Maslow's hierarchy of needs, which describes human needs for self-actualization and creative engagement in work, became a popular tool in this critique. This issue was acknowledged, but did not gain much traction otherwise.

The second critique had to do with quality. Workflows optimized for a particular time became inflexible as work conditions changed. Quality, in both analytic and synthetic manifestations, transformed the nature of work through a variety of movements, ranging from total quality management to Six Sigma to more qualitative notions of business process reengineering (Hammers and Champy, 1991). Under the influence of the quality movement, workflows became the subject of much scrutiny and optimization efforts. Acknowledgement of the dynamic and changing nature of the demands on workflows came in the form of recognition of the phenomena associated with critical paths and moving bottlenecks.

The experiences with the quality movement made it clear that information flows are fundamentally different from the mass and energy flows which inspired the first forms of rational workflows. The low cost and adaptability of information flows were seen as enabling workflows that were at once highly rational in their organization and highly flexible, adaptable and responsive. These insights unleashed a whole range of information technology at workflows in manufacturing, services and pure information work. Flexible manufacturing systems, just-in-time inventory management, and other highly agile and adaptable systems of workflow are products of this era.

Examples
The following examples illustrate the variety of workflows seen in various contexts:


 * 1) In military planning, a "concept of operations" is a workflow that defines particular mission types
 * 2) In machine shops, particularly  job shops and flow shops, the flow of a part through the various processing stations is a work flow
 * 3) Insurance claims processing is an example of an information-intensive, document-driven workflow
 * 4) wiki.gis.com editing is an example of a stochastic workflow
 * 5) The Getting Things Done system is a model of personal workflow management for information workers
 * 6) In global software development, the concept of follow-the-sun describes a process of passing unfinished work across time zones.

Features and phenomenology

 * 1) Modeling:  Workflow problems can be modeled and analyzed using graph-based formalisms like Petri nets.
 * 2) Measurement: Many of the concepts used to measure scheduling systems in operations research are useful for measuring general workflows. These include throughput, processing time, and other regular metrics.
 * 3) Specialized connotations: The term workflow has specialized connotations in information technology, document management and imaging.  Since 1993, one trade consortium specifically focused on workflow management and the interoperability of workflow management systems has been the Workflow Management Coalition.
 * 4) Scientific workflows: Found wide acceptance in the fields of bioinformatics and cheminformatics in the early 2000s, where they successfully met the need for multiple interconnected tools, handling of multiple data formats and large data quantities. Also, the paradigm of scientific workflows was close to the well-established tradition of Perl scripting in life-science research organizations, so this adoption represented a natural step forward towards a more structured infrastructure setup.
 * 5) Human-machine interaction: Several conceptualizations of mixed-initiative workflows have been studied, particularly in the military, where automated agents play roles just as humans do. For innovative, adaptive, collaborative human work the techniques of human interaction management are required.

Workflow improvement theories
The key driver to gain benefit from the understanding of the workflow process in a business context is that the throughput of the workstream path is modelled in such a way as to evaluate the efficiency of the flow route through internal silos with a view to increasing discrete control of uniquely identified business attributes and rules and reducing potential low efficiency drivers. Evaluation of resources, both physical and human is essential to evaluate hand-off points and potential to create smoother transitions between tasks. Several workflow improvement theories have been proposed and implemented in the modern workplace. These include:


 * 1) Six Sigma
 * 2) Total Quality Management
 * 3) Business process reengineering
 * 4) Lean systems

As a way of bridging the gap between the two, significant effort is being put into defining workflow patterns that can be used to compare and contrast different workflow engines across both of these domains.

Workflow components
A workflow can usually be described using formal or informal flow diagramming techniques, showing directed flows between processing steps. Single processing steps or components of a workflow can basically be defined by three parameters:
 * 1) input description: the information, material and energy required to complete the step
 * 2) transformation rules, algorithms, which may be carried out by associated human roles or machines, or a combination
 * 3) output description: the information, material and energy produced by the step and provided as input to downstream steps.

Components can only be plugged together if the output of one previous (set of) component(s) is equal to the mandatory input requirements of the following component. Thus, the essential description of a component actually comprises only in- and output that are described fully in terms of data types and their meaning (semantics). The algorithms' or rules' description need only be included when there are several alternative ways to transform one type of input into one type of output – possibly with different accuracy, speed, etc.

When the components are non-local services that are invoked remotely via a computer network, such as Web services, additional descriptors (such as QoS and availability) also must be considered.

Workflow applications
Many software systems exist to support workflows in particular domains. Such systems manage tasks such as automatic routing, partially automated processing and integration between different functional software applications and hardware systems that contribute to the value-addition process underlying the workflow.