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A workflow consists of an orchestrated and repeatable pattern of business activity enabled by the systematic organization of resources into processes that transform materials, provide services, or process information. It can be depicted as a sequence of operations, declared as work of a person or group, an organization of staff, or one or more simple or complex mechanisms.
From a more abstract or higher-level perspective, workflow may be a view or representation of real work, thus serving as a virtual representation of actual work. The flow being described may refer to a document, service or product that is being transferred from one step to another. 
- 1 Historical development
- 2 Workflow management system
- 3 Related concepts
- 4 Examples
- 5 Features and phenomenology
- 6 Workflow improvement theories
- 7 Workflow components
- 8 Workflow applications
- 9 See also
- 10 References
- 11 Further reading
- 12 External links
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 Frederick Taylor and Henry Gantt. Rudolf Laban and Warren Lamb contributed to this in England. Together, Taylor and Gantt 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 implementation of a workflow from this era, the early thinking around work was far more sophisticated than is often commonly understood. The notion of flow was more than a sequential breakdown of processing. The common conceptual models of modern operations research, including job shops and queuing systems (Markov chains), 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). 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 book The Organization Man by William H. Whyte, published in 1956, culturally captured the nature of work in this era.
In 1995, some people in 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.
During the 1980s, two aspects of workflow organization drew heavy criticism. First, the methods pioneered by Taylor modeled humans as simple automata. 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, then to more qualitative notions of business process re-engineering (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; this 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.
Workflow management system
See main article Workflow management system
The concept of workflow is closely related to several fields in operations research and other areas 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.
- Processes: A process is a more general notion than workflow and can apply to physical or biological processes, for instance; whereas a workflow is typically a process or collection of processes described in the context of work, such as all processes occurring in a machine shop.
- 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 execute the same plan repeatedly.
- Flow control is a control concept applied to workflows, to distinguish from static control of buffers of material or orders, to mean a more dynamic control of 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, such as just-in-time or just-in-sequence.
- 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.
The following examples illustrate the variety of workflows seen in various contexts:
- In machine shops, particularly job shops and flow shops, the flow of a part through the various processing stations is a work flow.
- Insurance claims processing is an example of an information-intensive, document-driven workflow.
- Wikipedia editing is an example of a stochastic workflow.
- The Getting Things Done system is a model of personal workflow management for information workers.
- In software development, support and other industries, the concept of follow-the-sun describes a process of passing unfinished work across time zones.
- In traditional offset and digital printing, the concept of workflow represents the process, people and usually software technology (RIPs raster image processors or DFE digital front end) controllers that play a part in pre/post processing of print-related files. e.g. PDF pre-flight checking to make certain that fonts are embedded or that the imaging output to plate or digital press will be able to render the document intent properly for the image-output capabilities of the press that will print the final image.
- In Scientific experiments, the overall process (tasks and data flow) can be described as a Directed Acyclic Graph (DAG). This DAG is referred to as a workflow, e.g. Brain Imaging workflows.
- In healthcare data analysis, a workflow can be used to represent a sequence of steps which compose a complex data analysis (data-search and data-manipulation steps).
- In Service-oriented architectures an application can be represented through an executable workflow, where different, possibly geographically distributed, service components interact to provide the corresponding functionality, under the control of a Workflow Management System.
Features and phenomenology
- Modeling: Workflow problems can be modeled and analyzed using graph-based formalisms like Petri nets.
- 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.
- 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.
- Scientific workflow system: 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 programming in life-science research organizations, so this adoption represented a natural step forward towards a more structured infrastructure setup.
- 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 analysis: Workflow systems allow users to develop executable processes with no familiarity with formal programming concepts. Automated workflow analysis techniques can help users analyze the properties of user workflows to conduct verification of certain properties before executing them, e.g. analyze flow control or data flow. Examples of tools based on formal analysis frameworks have been developed and used for the analysis of scientific workflows and can be extended to the analysis of other types of workflows.
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:
- Six Sigma
- Total Quality Management
- Business Process Reengineering
- Lean systems
- Theory of Constraints
- Neural Workflow
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:
- input description: the information, material and energy required to complete the step
- transformation rules, algorithms, which may be carried out by associated human roles or machines, or a combination
- 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.
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.
- Bioinformatics workflow management systems
- Business process automation
- Business process management
- Business process modeling
- Business-driven development
- Computer-supported collaboration
- Enterprise content management
- Process architecture
- Process-driven application
- Project management
- Scientific workflow system
- Smart contracts
- See e.g., ISO 12052:2006, ISO.org
- See e.g., ISO/TR 16044:2004, ISO.org
- Taylor, 1919
- Pinedo, 2001
- Goldratt, E., 1996
- http://ceiton.com/CMS/EN/CEITON-CTWS-AVinvest.pdf Production planning and control using workflows
- Brain Image Registration Analysis Workflow for fMRI Studies on Global Grids, Computer.org
- A grid workflow environment for brain imaging analysis on distributed systems, Wiley.com
- Huser, V.; Rasmussen, L. V.; Oberg, R.; Starren, J. B. (2011). "Implementation of workflow engine technology to deliver basic clinical decision support functionality". BMC Medical Research Methodology 11: 43. doi:10.1186/1471-2288-11-43. PMC 3079703. PMID 21477364.
- Service-Oriented Architecture and Business Process Choreography in an Order Management Scenario: Rationale, Concepts, Lessons Learned, ACM.org
- Workflow management for soft real-time interactive applications in virtualized environments, Elsevier.com
- Curcin, V.; Ghanem, M.; Guo, Y. (2010). "The design and implementation of a workflow analysis tool". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 368 (1926): 4193. doi:10.1098/rsta.2010.0157.
- Ryan K. L. Ko, Stephen S. G. Lee, Eng Wah Lee (2009) Business Process Management (BPM) Standards: A Survey. In: Business Process Management Journal, Emerald Group Publishing Limited. Volume 15 Issue 5. ISSN 1463-7154. PDF
- Khalid Belhajjame, Christine Collet, Genoveva Vargas-Solar: A Flexible Workflow Model for Process-Oriented Applications. WISE (1) 2001, IEEE CS, 2001.
- Marlon Dumas, Wil van der Aalst, Arthur ter Hofstede: Process-Aware Information Systems, Wiley, ISBN 0-471-66306-9
- Layna Fischer (ed.): 2007 BPM and Workflow Handbook, Future Strategies Inc., ISBN 978-0-9777527-1-3
- Layna Fischer: Workflow Handbook 2005, Future Strategies, ISBN 0-9703509-8-8
- Layna Fischer: Excellence in Practice, Volume V: Innovation and Excellence in Workflow and Business Process Management, ISBN 0-9703509-5-3
- Thomas L. Friedman: The World Is Flat: A Brief History of the Twenty-first Century, Farrar, Straus and Giroux, ISBN 0-374-29288-4
- Keith Harrison-Broninski. Human Interactions: The Heart and Soul of Business Process Management. ISBN 0-929652-44-4
- Holly Yu: Content and Work Flow Management for Library Websites: Case Studies, Information Science Publishing, ISBN 1-59140-534-3
- Wil van der Aalst, Kees van Hee: Workflow Management: Models, Methods, and Systems, B&T, ISBN 0-262-72046-9
- Setrag Khoshafian, Marek Buckiewicz: Introduction to Groupware, Workflow and Workgroup Computing, John Wiley & Sons, ISBN 0-471-02946-7
- Rashid N. Kahn: Understanding Workflow Automation: A Guide to Enhancing Customer Loyalty, Prentice Hall, ISBN 0-13-061918-3
- Dan C. Marinescu: Internet-Based Workflow Management: Towards a Semantic Web, John Wiley & Sons, ISBN 0-471-43962-2
- Frank Leymann, Dieter Roller: Production Workflow: Concepts and Techniques, Prentice Hall, ISBN 0-13-021753-0
- Michael Jackson, Graham Twaddle: Business Process Implementation: Building Workflow Systems, Addison-Wesley, ISBN 0-201-17768-4
- Alec Sharp, Patrick McDermott: Workflow Modeling, Artech House Publishers, ISBN 1-58053-021-4
- Toni Hupp: Designing Work Groups, Jobs, and Work Flow, Pfeiffer & Company, ISBN 0-7879-0063-X
- Gary Poyssick, Steve Hannaford: Workflow Reengineering, Adobe, ISBN 1-56830-265-7
- Dave Chaffey: Groupware, Workflow and Intranets: Reengineering the Enterprise with Collaborative Software, Digital Press, ISBN 1-55558-184-6
- Wolfgang Gruber: Modeling and Transformation of Workflows With Temporal Constraints, IOS Press, ISBN 1-58603-416-2
- Andrzej Cichocki, Marek Rusinkiewicz, Darrell Woelk: Workflow and Process Automation Concepts and Technology, Kluwer Academic Publishers, ISBN 0-7923-8099-1
- Alan R. Simon, William Marion: Workgroup Computing: Workflow, Groupware, and Messaging, McGraw-Hill, ISBN 0-07-057628-9
- Penny Ann Dolin: Exploring Digital Workflow, Delmar Thomson Learning, ISBN 1-4018-9654-5
- Gary Poyssick: Managing Digital Workflow, Prentice Hall, ISBN 0-13-010911-8
- Frank J. Romano: PDF Printing & Workflow, Prentice Hall, ISBN 0-13-020837-X
- James G. Kobielus: Workflow Strategies, Hungry Minds, ISBN 0-7645-3012-7
- Alan Rickayzen, Jocelyn Dart, Carsten Brennecke: Practical Workflow for SAP, Galileo, ISBN 1-59229-006-X
- Alan Pelz-Sharpe, Angela Ashenden: E-process: Workflow for the E-business, Ovum, ISBN 1-902566-65-3
- Stanislaw Wrycza: Systems Development Methods for Databases, Enterprise Modeling, and Workflow Management, Kluwer Academic/Plenum Publishers, ISBN 0-306-46299-0
- Database Support for Workflow Management, Kluwer Academic Publishers, ISBN 0-7923-8414-8
- Matthew Searle: Developing With Oracle Workflow
- V. Curcin and M. Ghanem Scientific workflow systems - can one size fit all? paper in CIBEC'08 comparing scientific workflow systems.
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