News Propogation Application

notation      its motivation      method for its use

The diagram above represents the starting point for the implementation of the news propogation application system.  It simply consists of a set of workplaces, with one workplace for each employee.  The implementation of each workplace is given by clicking on its name (in red).


Workplace Component

notation      its motivation      method for its use

The diagram above represents the starting point for the implementation of a workplace.  It closely supports the news propogation process (to see this click on the red arrow at the top left of the diagram).  The implementations of the components of the workplace depend on whether or not a process support system is used.  Click on the red square to see implementations without process support.  Click on the red circle to see the implementations with process support.  Click on the red diamond to see the implementations reoriented towards their systems implementation.


Implementation Without Process Support
Implementations Without Process Support

notation      its motivation      method for its use


Implementation With Process Support
Implementations With Process Support

notation      its motivation      method for its use

The difference between this and the alternative implementations is that the process support capability can maintain surrogates for the human role and for the applications.  These surrogates can (at least partially) know the current state of the humans and applications and can perform tasks on their behalf (for instance loading tools required for particular tasks, or packaging data obtained from legacy databases, or informing other human roles of actions required of them for the task in hand).


Implementation Reorganised
Implementations Reorganised Into Systems

notation      its motivation      method for its use

This regroups the components of the other implementations.


Applications Architecture View


DPA Architecture

notation      its motivation      method for its use

The starting point for the design of an architecture for the DPA news agency is given by the above diagram.  The DPA news agency is considered to be part of a news propogation system.  This news propogation system is represented by the outer structure in the diagram above.  Its implementation is represented by the inner structure of that diagram and consists of two components interacting with each other.  The implementations of these two components can be seen by clicking on their names (in red).  The combination of these implementations can be seen by clicking on the name at the top, news propogation


Notation
POSD Notation Used For This Design

The key features of the POSD (Process Oriented Systems Design) notation are:

Diagrams - The structure of a system is represented by a set of diagrams.    The system may be a human system, an IT system, another system, or a hybrid of these.

Outer and Inner Structures - Each diagram has an outer structure (using thick lines and large letters) and an inner structure (using thin lines and small letters).  The inner structure provides an implementation of the outer structure (in the sense that it achieves all of the behaviour of the outer structure).

Meaning of Boxes - A box represents the behaviour of a system.  The system may be a human system, an IT system, another system, or a hybrid of these.

Meaning of Touching - The fact that two boxes touch is both:

- a statement that the behaviours (which they represent) interact with (and thereby modify) each other and

- a promise that later diagrams will define how they interact .

Redeeming of Promises Made By Touching  - The later diagrams may redeem the promise by showing that either :

- the touching behaviours have a shared component behaviour

- or one of the touching behaviours touches a component behaviour of the other

- or components of the touching behaviours touch

The second and third alternatives can be seen as deferred versions of the first.

Alternative implementations may be provided for any behaviour.

Shading on a box means that there may be more than one instance of the component behaviour represented by that box.


Motivation
Motivation For POSD

The Wire Syndrome

Hardware engineers are more advanced than software engineers in describing their systems in semi-formal graphical notations.  They draw diagrams containing boxes connected with lines.  At the lowest level the diagrams represent board layouts.  At the highest level they represent major components (processors, stores, etc) and their connections.  However if one examines the high level diagrams one observes a curious feature, although the boxes in the diagrams are at a very high level of abstraction, the lines are at a low level, essentially corresponding to wires in the eventual implementation.  It seems that it is difficult to create abstractions of the connections between hardware components though easy to abstract the components themselves.  This phenomenon has been referred to as the wire syndrome.  It can cause problems by forcing engineers to take detailed decisions about interfaces too early in the design process.

The Wire Syndrome In Business Process Reengineering

Recently business reengineers (and software engineers) have been trying to model business (and engineering) processes.  They have used boxes to represent the roles within the processes and lines to represent the interactions between the roles.  If one examines their diagrams one observes the wire syndrome manifesting itself again.  The boxes in the diagrams represent high level abstractions like divisions, customers and suppliers but the lines represent relatively low level abstractions such as passing a document, filing a document, updating a database, or sending a message.  This causes problems because it forces (or encourages) businessmen to reengineer their businesses at the wrong level, worrying about the operation of their post rooms rather than the structure of their value-chains.

Desire For Lego-Brick Style Of Systems Engineering

It should be possible to overcome the wire syndrome by treating both boxes and lines as the same type of object to be dealt with at the same level of abstraction.  People have for some years characterised this approach as a lego-brick style of systems engineering.  They have imagined a set of components (the lego-bricks) that can be readily plugged together to make larger components and ultimately systems.  The Object Oriented design community might claim that they have already achieved this goal.  They are certainly nearer than any previous attempt.  However as well as the objects that give the object oriented approach its name they have introduced other low level entities to achieve their approach.  They have message passing to connect objects and method interfaces at the points where messages are sent and received by objects.  Hence they have created the wire syndrome again with message passing as its wires.  Their objects might be at a high level of abstraction but their connections are at a low level.

Recognising The Fractal Structure Of Systems

It seems that the only way to overcome the wire syndrome is to insist that systems are built from just one type of object and that the entities used to plug together objects in systems must themselves be objects.  This is the key objective of POSD.  However this has meant recognising that systems are essentially fractal in structure, whenever one looks at the boundary of two objects one finds another object.  This is the structuring phenomenon observed in geological systems (the UK coastline) and biological systems (the edges of leaves).  The key contribution of POSD is to recognise that one can only achieve the highly desirable lego-brick style of systems engineering if one recognises that systems are fractal in structure.  Other design methods have fudged this issue by creating special low level connectors (data flow, message passing, events, receive/send ports, lego-brick nipples) to plug their lego-bricks together.

If one considers any system in detail the fractal view seems reasonable.  At one level the system may be described as a set of application packages interacting with each other.  However when one looks at the interactions closely one finds various complex mechanisms including database systems, communications systems, dialogue systems, mail systems and procedure call mechanisms.  At a lower level the communications systems (and database systems) have multi-level nested structures (as in the ISO seven layer model).  POSD is simply recognising the general applicability of this existing view.


Method
Method For Using POSD

The authors of this script and others have now built up a body of experience in the use of the POSD notation.  Comparison of their experiences has shown that they all conformed to the process shown in the following diagram:

The diagram can be thought of as representing four people (or teams of people) operating in parallel with each other, performing the four roles of Understanding, Structuring, Changing and Implementing, and interacting with each other as shown in the diagram:

Understanding - the aim of the understanding role is to understand at a detailed level the systems that are currently in place and that will need to be changed - for this role the wire syndrome is not a significant problem, the objective is simply to collect as much information as possible - using many notations may help because they may highlight different views of the systems even if they restrict other views - notations such as SSADM diagrams, object oriented design, process diagrams, Jackson diagrams, and petri nets will be useful to this role

Structuring - the aim here is to see the wood from the trees, to extract many different high level views of the systems under consideration from the mass of detail collected by the understanding role -  some of these views will be views of the systems as they are but at a higher level of abstraction than has been produced by the understanding role, some will be new views showing what might be possible - the best of these new views will provide the outcome from this role, specifying what form the systems should take in the future - it is this role that needs the freedom of the POSD notation

Changing - the aim here is to change the detailed view of the systems to reflect the new insights developed by the structuring role - the most appropriate notations for this role will be those used in the understanding role

Implementing - the aim here is to realise the new detailed view in actual changes to the systems under consideration - in the past this would be the most resource intensive part of the process, the structural models created by the changing role would be hard wired into the systems using conventional programming languages - now there are systems integration frameworks which can be used to simplify this role, these frameworks operate at the level of the models created by the changing role and allow components to be integrated at that level

The output from the implementing role provides the input for the understanding role in the next round of systems development


DPA Business System

notation      its motivation      method for its use

This diagrao show the news propogation business as having value-chain, organisation and process components.   The implementations of these three components can be seen by clicking on their names (in red).


DPA IT System

notation      its motivation      method for its use

This diagram show the news propogation IT system as having process, application and (basic) system components.   The implementations of these three components can be seen by clicking on their names (in red).


DPA Business And IT Systems

notation      its motivation      method for its use

The two diagrams (for the news propogation business system and news propogation IT system) can be combined in one "bone" shaped diagram to emphasise the shared component (news propogation process) between the two systems.   The implementations of the five components shown can be seen by clicking on their names (in red).


DPA Business Architecture


News Propogation Process

notation      its motivation      method for its use

The diagram above represents the starting point for the implementation of the news propogation process.  It is formed by "folding over" the detailed implementation of the new agency organisation (which can be seen by clicking on the arrow sign at the top left of the diagram).  That is to say it uses one role, news agency role, to represent all roles with human involvement in the organisation (reporter, editor, augmenter, caster, head of desk, and newscast manager) and recognises that they have three types of interaction with each other and with the news source and news end-user (namely news packages, control and customer service interactions).  The implementations of the components of the process can be seen by clicking on their names (in red).


News Agency Role Component

notation      its motivation      method for its use

The diagram on the left above gives the implementation of the news agency role of the news propogation process.  It contains the human playing the role together with the tasks, messages and information this human receives or sends to other humans and the operations it performs on the information.

The diagrams on the right above give the different types of news agency role.  They all conform to the implementation given on the left.


Customer Service Component

notation      its motivation      method for its use

The above diagram gives the implementation of the customer service component of the news propogation process.  This component represents the shared behaviour between the news agency role and the end-user (or a news agency role in another news agency).  It involves transfer of payment and sales/marketing information and operations on this information.


Control Component

notation      its motivation      method for its use

The diagram to the right above gives the implementation of the control component of the news propogation process.  It contains the tasks scheduled by managers (eg CVD, head of desk, etc) for other roles (eg reporters, editors, etc) and the tasks which are triggered by calendar events (eg presidents birthday) together with the workpool system which supports management of these tasks (ie their recording, scheduling, allocation, reporting, etc).

It contains the suggestions, prompts and rules which flow as messages between managers and other roles together with the mail system which supports this message flow.

The diagrams on the left above give the different types of control component.  They all conform to the implementation given on the right.


News Package Component

notation      its motivation      method for its use

The diagrams on the bottom left above give the different types of news package component for the news propogation process.  The diagram on the bottom right above gives the implementation to which these all conform.  It contains an archiving system for storing news packages, the information contained in the packages, and the operations which can be performed on this information.  The implementations for the news information and the news operation components can be seen by clicking on their names (in red).


News Package Operation Component

notation      its motivation      method for its use


News Package Information Component

notation      its motivation      method for its use


Source Component

notation      its motivation      method for its use

For the purposes of the news propogation process the implementation of the news source can be that given above.


End-User Component

notation      its motivation      method for its use

For the purposes of the news propogation process the implementation of the news end-user can be that given above.


More Detailed Implementation Of Process

notation      its motivation      method for its use


End-to-End Process View


News Propogation Organisation

notation      its motivation      method for its use

The diagram above represents the starting point for the implementation of the news propogation organisation.  It shows the news propogation organisation as comprising a number of news agencies of which DPA is just one example.  The implementations of a news agency component can be seen by clicking on its name (in red).


News Agency Component Of Organisation
News Agency Component

notation      its motivation      method for its use

The diagram above represents the implementation of one news agency.  It shows the agency as comprising a number of bureaux.  These will normally be sited at different locations.  The implementations of a bureau component can be seen by clicking on its name (in red).


News Bureau Component Of Organisation
News Bureau Component

notation      its motivation      method for its use

The bottom diagram above represents the implementation of one news bureau.  It shows the bureau as comprising a number of services.  The implementations of a service component can be seen by clicking on its name (in red).  Examples of bureaux and the services they contain can be seen by clicking on the name, bureaux (in red).


Examples Of News Bureaux

notation      its motivation      method for its use

The diagrams above give examples of a number of bureaux and the services they contain.  The main bureau of DPA is in Hamburg.  It contains a basic service that employs most of the news processing staff of the organisation and that processes the complete range of news.  It has English, Spanish and Arabic services that tailor the complete range of news for English, Spanish and Arabic speaking communities.  It has a radio service that creates and distributes news in audio format.  It has a European service that collects and tailors news for distribution in Europe.

There are a set of regional news bureaux sited in the regions of Germany and the rest of Europe.  These collect and process news from their regions.

The Washington and Buenos Aires bureaux act as regional bureaux for the USA and Latin America.  They also take on the roles of  English and Spanish services during the German night time (when the main (Germany based) versions of these services are inactive).


News Service Component Of Organisation
News Service Component

notation      its motivation      method for its use

The bottom diagram above represents the implementation of one news service.  It shows the bureau as comprising a number of news desk and casting components.  The implementations of the two components can be seen by clicking on their names (in red).  A full implementation of a service formed by combining the implementations of its components can be seen by clicking on the name, service (in red).


News Desk Component Of Organisation
News Desk Component

notation      its motivation      method for its use

The diagram above represents the implementation of one news desk.  It shows the desk as comprising a number of capturing and editing components.  The implementations of the two components can be seen by clicking on their names (in red).  Examples of news desks can be seen by clicking on the name, desk (in red).  The position of capturing, editing and casting within the news propogation value chain can be seen by clicking on the arrow at the top left of the diagram.


Examples Of News Bureaux
Examples Of News Desks

notation      its motivation      method for its use

The above diagrams show the different types of news desk.


Source of News
Source Of News Component

notation      its motivation      method for its use

The above diagram shows the implementation of the source of news.  It contains some news worthy event together with the raw news package that a reporter extracts from this event.


Capturing Component of Organisation
Capturing Component

notation      its motivation      method for its use

The above diagrams show the implementation of the capturing system.  Its main component is the reporter (including both the human news reporter and all the IT (and other systems) required to support his/her activities).  The reporter creates the raw news package from the news event and forms it into a more polished revisable news package.  This is enhanced by the augmenter adding a unique identification number (UNO) and improving spelling, picture quality, sound quality, etc.  There will be different types of Reporter (as well as Augmenter and Editor) for each media type as in the following diagrams.


Editing Component of Organisation
Editing Component

notation      its motivation      method for its use

The above diagram shows the implementation of the editing system.  Editors receive revisable news packages from the capturing system and receive previously published news packages from the casting system.  They edit these packages and combine them to form finished news packages for the casting system.  The head of desk interacts with the editors to determine the themes that are to be covered by the finished news packages.  The head of desk also interacts with reporters in the capturing system to determine the events that must be captured in revisable news packages.  The head of desk provides advisory information to the casting system to inform it what news packages to expect in the future.  It receives advisory information from other casting systems as well as customer services (marketing, sales and payment).  The activities of the head of desk are controlled by the agency shift manager (CVD) reporting to the chief editor.


Casting Component of Organisation
Casting Component

notation      its motivation      method for its use

The above diagrams shows the implementation of the casting system.  The caster takes finished news packages from the editor and (occasionally if urgent enough) revisable news packages from reporters and forms them into published news packages.  In some cases the caster is an IT system without the human participation.  For instance there is a database casting services that reporters and editors update via the revisable and finished news package interactions and end-users and others interrogate via the published news package interaction.  Or for instance the broadcast casting service automatically broadcasts to end users and others any revisable or finished news packages it receives.  More selective casting services involve some human participation.  The newscast manager receives advisory information from heads of desk and provides this to end-users and others.  He/she also supplies them with customer services (marketing, sales and payment).  He/she is controlled by the agency shift manager (CVD).


End-User Of News

notation      its motivation      method for its use

The above diagram shows the implementation of the end-user system.  It contains some news hungry business together with the advisory news package, published news package, and customer service provided to that end-user.


More Detailed Implementation Of Service
More Detailed Implementation Of Service Component

notation      its motivation      method for its use

The top diagram combines the implementations of Capturing, editing and casting components to give a more detailed view of the implementation of a news service.  The bottom diagram shows how the service can now be reviewed as made up of control flow, advisory flow and news flow components interacting with each other.  The implementations of these components can be seen (highlighted in red) by clicking on the appropriate name (in red) in the lower diagram.


Control Flow

notation      its motivation      method for its use


Advisory Flow

notation      its motivation      method for its use


News Flow

notation      its motivation      method for its use


Organisation View


News Propogation System

notation      its motivation      method for its use

The diagram above represents the starting point for the implementation of the news propogation system view.  It simply consists of a set of workstations and central servers.  The implementation of each is given by clicking on its name (in red).


Workstation Component

notation      its motivation      method for its use

The structure is derived from the reorganisation of the applications architecture.  Click on the red arrow to see this reorganisation.


Central Server Component

notation      its motivation      method for its use


Systems Architecture View


News Propogation Value Chain

notation      its motivation      method for its use

The diagram above represents the starting point for the design of the news propogation value-chain.  At the left hand side of the value-chain are the original sources of news, the organisations and individuals engaged in newsworthy events.  Next to them (to their right) are the systems (human and IT) within news agencies that capture the news from these original sources and do the initial packaging of this news.  At the right hand side are the end-users (organisations or individuals) receiving the finally packaged news.  Next to them (to their left) are the systems (human and IT) that add value to the news in various ways on its journey from the original sources to the end users.  The implementations of the four components can be seen by clicking on their names (in red).  Example configurations of the value-chain can be seen by clicking on the name at the top, news propogation value-chain.


Value Adding Component of Value Chain
Value Adding Component

notation      its motivation      method for its use

The bottom pair of diagrams represent the two alternative implementation of the value adding component of the news propogation value chain.  The box on the left of the right hand implementation (clipping) represents the system (human and IT) that gathers together different news items and combines them into a finished news package.  The box to its right (casting) represents the system (human and IT) that prepares (or casts) news for publication outside a news agency (broadcasts to all customers or selectively sends to particular customers).  The recursive nature of the right hand implementation allows for the fact that a clipping system in one news agency may incorporate news published (cast) by another news agency (or the same news agency for that matter).  The implementations of two of its components can be seen by clicking on their names (in red).


Clipping Component of Value Chain
Clipping Component

notation      its motivation      method for its use

The bottom pair of diagrams above represent the alternative implementation of the clipping system.  This is the system (human and IT) that gathers together different news items and combines them into a finished news package.  The diagram represents the fact that it may comprise a series of zero, one or more editing systems.  The implementations of its editing component can be seen by clicking on its name (in red).


Examples of Value Chain Configurations
Example Value Chain Configurations

notation      its motivation      method for its use

The above diagrams show the three most typical configurations of the value-chain view developed above.  The first represents the case where news is gathered from an original source, edited with other news to form a finished news package, cast for publication, and delivered to the end user.  The second represents the less typical case where editing is missed out and raw news is published to the end user.  The third represents the case where a finished news package produced from one editing and casting system is later used as input to another editing and casting system.


Value Chain View