|This article is of interest to the following WikiProjects:|
- In this edit text is here copy/pasted from the Functional decomposition article.
- In this edit text is here copy/pasted from a PD source.
- In this edit text is here copy/pasted from a PD source.
- In this edit text is here copy/pasted from a PD source.
- In this edit text is here copy/pasted from the Functional flow block diagram, N2 Chart, Structured Analysis and Design Technique, IDEF0, and Business Process Modeling Notation articles.
- In this edit text is here copy/pasted from the HIPO article.
- In this edit text is here copy/pasted from the Business reference model article.
- In this edit text is here copy/pasted from the Functional Flow Block Diagram article.
- In this edit text is here copy/pasted from the Gantt Chart article.
Quotes about function models and functional model
The following section gives a listing of quotes, and sources, which could be used to further improve this article. This first set of quotes is arranged chronologically:
- It had previously been considered impossible to make a Gyro-Compass of the size the Navy required. But new techniques, including the application of electronics, enabled our engineers to have a satisfactory functional model operating within three months.
- "What it takes to launch an invasion..." LIFE, April 17, 1944 - Vol. 16, nr. 16. p. 105
- In this early text the term "functional model" is used meaning "working model", and not "graphical representation".
- If an organization desired to be ideally functional along this dimension, it would give people the widest latitude in choosing the form of their routine interactions and activities so that socially satisfying routines could emerge along with informal group leadership. Once these routines had emerged they would be left strictly alone. Once again, as soon as we state this ideally functional model, its potential for perversion becomes apparent. Such an unidimensional system could provide a very "groupy group" but one without direction and with a control over members that would result in stultifying conformity rather than self growth.
- A functional model must thus achieve two aims in order to be of use. It must furnish a throughput description mechanics capable of completely defining the first and last throughput states, and perhaps some of the intervening states. It must also offer some means by which any input, correctly described in terms of this mechanics, can be used to generate an output which is an equally correct description of the output which the actual system would have given for the input concerned. It may also be noted that there are two other things which a functional model may do, but which are not necessary to all functional models. Thus such a system may, but need not, describe the system throughputs other than at the input and output, and it may also contain a description of the operation which each element carries out on the throughput, but once again this is not
- William Gosling (1962) The design of engineering systems. p. 23
- This seems one of the first times that the term "functional model" is used in an (electrical) engineering context. In the 1960s the term "function model" is used more often in texts about physics or about mathematics. The term "functional model" is more often used in social science texts.
- It will appear also, as the 'functional' model discussed earlier might lead us to anticipate, that institutions which are apparently economic may also, and perhaps more importantly, serve other ends besides utilitarian ones
- John Beattie (1966) Other Cultures: Aims, Methods and Achievements in Social Anthropology. p. 183
- This quote stipulates a "functional model" in some social anthropology theory.
- ... Functional analysis, as an expository and explanatory tool is a convenient way for dealing systematically with relations among such parts as well as with the role that each part plays in relation to the whole. The organization as a system and the various subsystems within can be conceived as having needs (functional requirements). Any structural part is said to have a function when it contributes to the fulfilment of a need. On the other hand, when the effects of the part hinder this fulfilment one speaks of dysfunctional consequences or of the part as dysfunctional with respect to the above need. From the above it becomes evident that a certain part or social pattern can have both functional and dysfunctional consequences for different needs of the system.... (p. 58)
.... we admit that human relations students have pro-managerial values and that such values have determined the problems studied (how to increase productivity) and the conceptual framework used (narrow scope, functional model), this is not a reason to a priori their statement as false. (p. 170-171)
- Nikos P. Muzelēs (1968) Organisations and Bureaucracy: An Analysis of Modern Theories.
- In this 1968 organizational theory textbook the term "functional model" (might) refer to the functional analysis toolset, a tool from the systems approach toolbox.
- Function approach: A function model is proposed for the analysis and design of the way companies determine what is going to be produced. This model is a set of functions with their interrelations.
- Robert W. Grubbström, H. H. Hinterhuber, Janerik Lundquist (1991) Production economics: issues and challenges for the 90's. p. 344
- What is important in a functional model is not what Christ accomplished on our behalf, but how Christ did it. Of cardinal importance is not the content on the objective level, but the effect on the subjective and social level.
- Daniël J. Louw (1999) A Mature Faith. p. 42
- A functional model is a composition of processes having remote states definitions.... Specifying processes could be difficult for the designer unfamiliar with formal methods. Tools supporting functional model elaboration have been designed in the process calculus community. For instance, based on scenarios specified as sequence, diagrams or message sequence charts, FSP expressions could be generated to assist the [software] architect.
- Steffen Becker, Frantisek Plasil, Ralf H. Reussner (2008) Quality of Software Architectures Models and Architectures. p.62
- Functional model is – a systematic way to describe a system’s functionality
- Chiradeep Sen (2013) "ME-402 Workshop: Functional Modeling"
A System engineering tool for FMS Planning
Source: Major Robert E. Schafrik (ca. 1982) "A System engineering tool for FMS Planning"
- The Function Model is essentially a graphical technique for representing the activities (or functions) of the system... which the manager deems important... This model deals with inter-reationships between activities and does not take into account the time required to accomplish the activity.
- p. 29
- The first step in constructing any model is to define the system. This is done by declaring what activity will be modeled. - For example, an 'activity. "Conduct an FMS Program" can be modeled provided the boundaries and restrictions of the system are specified. Thus, the purpose, viewpoint, and context of the model must be explicitly described.
The next step is preparation of the data. This is done by listing all the activities which are required to accomplish the activity being modeled. Personal knowledge, information from experts, consultation with reference material, etc. are all sources of this information. The activities are then grouped into logical sets. They will normally fall into a hierarchical pattern, so the next step is to arrange them that way. The principal activity being modeled is labeled A0. A basic rule is that an activity cannot be further broken down (or "decomposed" as the systems analysts say) into more than six activities. Thus, the AO activity (or "Node") can be broken down into A1 through A6; Likewise, A1 can be broken down into A 11 through A16, etc. (Of course, an activity need not be broken down into 6 activities if fewer such activities are adequate). The activity described by an action verb with a subject. A listing of activities in hierarchical order is called a Node Tree. It is this Node Tree which serves as the building block for the model.
Each activity generally has information input into it and output from it. The activity changes the input information into the output information. By convention, the inputs are shown entering the activity box from the left and the output exiting the box to the right. Every activity must have at least one control. This control provides the required rules, performance criteria, and evaluation data by which the activity accomplishes its mission. In other words, the control serves as the executive. By convention, if an item is both an input and a control, it is only shown as a control. Thus, every activity must have a control and an output, but need not have an input. The controls are shown entering the activity box from the top.
Activities can accomplish their mission through the application of physical processes and equipment, called mechanisms. If it is useful to indicate the mechanisms on the model, they are shown entering the activity box from the bottom.
- p. 32-33
Integrative Definition for Functional Modeling (IDEF0) (1993)
IFIPS (1993) Announcing the Standard for Integrative Definition for Functional Modeling (IDEF0). Draft Federal Information. Processing Standards Publication 183. December 21. 1993.
- During the 1970s, the U.S. Air Force Program for Integrated Computer Aided Manufacturing (ICAM) sought to increase manufacturing productivity through systematic application of computer technology. The ICAM program identified the need for better analysis and communication techniques for people involved in improving manufacturing productivity. As a result, the ICAM program developed a series of techniques known as the IDEF (ICAM Definition) techniques which included the following:
- IDEF0, used to produce a "function model". A function model is a structured representation of the functions, activities or processes within the modeled system or subject area.
- IDEF1, used to produce an "information model". An information model represents the structure and semantics of information within the modeled system or subject area.
- IDEF2, used to produce a "dynamics model". A dynamics model represents the time-varying behavioral characteristics of the modeled system or subject area.
- In 1983, the U.S. Air Force Integrated Information Support System program enhanced the IDEF1 information modeling technique to form IDEF1X (IDEF1 Extended), a semantic data modeling technique
- An important aspect of this ICAM definition is, that it implicitly acknowledged that in the modelling for information systems development different kind of models can be used to model a systems. This idea is formalized by John Zachman in his framework, and in other Enterprise Architecture view models.
- As a function modeling language, IDEF0 has the following characteristics:
- It is comprehensive and expressive, capable of graphically representing a wide variety of business, manufacturing and other types of enterprise operations to any level of detail.
- It is a coherent and simple language, providing for rigorous and precise expression, and promoting consistency of usage and interpretation.
- It enhances communication between systems analysts, developers and users through ease of learning and its emphasis on hierarchical exposition of detail.
- It is well-tested and proven, through many years of use in Air Force and other government development projects, and by private industry.
- It can be generated by a variety of computer graphics tools; numerous commercial products specifically support development and analysis of IDEF0 diagrams and models.
- In addition to definition of the IDEF0 language, the IDEF0 methodology also prescribes procedures and techniques for developing and interpreting models, including ones for data gathering, diagram construction, review cycles and documentation.
- p. vi
- With the development of IDEF0 and similar modelling languages, the function model perspective is developed into a functional modeling language.
For now I have just collected the above quotes, which are a indication of how the term emerged in different fields, and with different meaning -- Mdd (talk) 00:46, 25 May 2013 (UTC)/ 22:31, 25 May 2013 (UTC)
More general, in the 1960s the term "Functional model" seem to have appeared in a range of social sciences from physiology, biology, anthropology, sociology, to economics, political science, and cultural studies, see here. For example in titles of books, and articles:
- Graham Pyatt (1965) A Production Functional Model. University of Cambridge, Department of Applied Economics,
- Yvonne de Sinson Norton (1966) Toward a Conceptual Structuro-functional Model of Progressive Myelin-reflex Maturation (leading Toward Beginning Cognitive Function) During the First Six Months of Life. University of Southern California,
- Roy E. Jones (1967) The Functional Analysis of Politics: An Introductory Essay. Taylor & Francis
- Robert W. Avery (1969) A functional model of the life process
- Laurence R. Young, Jacob L. Meiry, Joel S. Newman, James E. Feather (1969) Research in Design and Development of a Functional Model of the Human Nonauditory Labyrinths. Vol 32 (3), Aerospace Medical Research Laboratories. ,Zoeken in een bibliotheek
- J. Peter Kincaid (1969) A Functional Model of Memory Based on Physiological and Verbal Learning Data. Air Force Human Resources Laboratory, 1969
Even more general, in the TU Delft library collection catalogue the term "function model" occurred 216 times in book titles, see , and the term "functional model" 131 times, see . Over time (number of times the word function model - functional model occurred in the title):
- 1960-1969 : (2) -
- 1970-1979 : (6) - (5)
- 1980-1989 : (10) - (12)
- 1990-1999 : (15) - (5)
- 2000-2009 : (60) - (49)
- 2010-2019 : (5) - (10)
The University of Amsterdam library gives 39,075 and 12,448 results in book and article titles, see  and . Over time (number of times the word function model - functional model occurred in the title or text):
- Before 1966 : (38) - (31)
- 1966 To 1976 : (562) - (338)
- 1977 To 1987 : (2,830) - (1,028)
- 1988 To 1999 : (10,301) - (3,213)
- After 1999 : (26,798) - (8,135)
Taken into account that the number of scientific publications has grown exponentially as well, one could still say:
- the term has become more popular every decade since the 1960s,
- both in the domain of the technical sciences (systems and software engineering) as in the social sciences
History section: text about Gantt charts removed
The following text has been removed from the history section:
- The first known Gantt chart was developed in 1896 by Karol Adamiecki, who called it a "harmonogram". Because Adamiecki did not publish his chart until 1931 - and in any case his works were published in either Polish or Russian, languages not popular in the West - the chart now bears the name of Henry Gantt (1861–1919), who designed his chart around the years 1910-1915 and popularized it in the West.
- H.L. Gantt, Work, Wages and Profit, published by The Engineering Magazine, New York, 1910; republished as Work, Wages and Profits, Easton, Pennsylvania, Hive Publishing Company, 1974, ISBN 0-87960-048-9.
- Gerard Blokdijk, Project Management 100 Success Secrets, Lulu.com, 2007, ISBN 0-9804599-0-7, Google Print, p.76
- Peter W. G. Morris, The Management of Projects, Thomas Telford, 1994, ISBN 0-7277-2593-9, Google Print, p.18
The reason is, that those charts are no examples of early functional modelling, while there are other examples of early activity models which would be more appropriate to mention. -- Mdd (talk) 23:28, 10 October 2014 (UTC)