Pattern Template 2

From ViaNovaArchitecturaWiki

In the introduction to his patterns book, Christopher Alexander describes the standard form of describing a pattern:

“For convenience and clarity, each pattern has the same format. First, there is a picture, which shows an archetypal example of that pattern. Second, after the picture, each pattern has an introductory paragraph, which sets the context for the pattern, by explaining how it helps to complete certain larger patterns. Then there are three diamonds to mark the beginning of the problem. After the diamonds there is a headline, in bold type. This headline gives the essence of the problem in one or two sentences. After the headline comes the body of the problem. This is the longest section. It describes the empirical background of the pattern, the evidence for its validity, the range of different ways the pattern can be manifested in a building, and so on.
Then, again in bold type, like the headline, is the solution—the heart of the pattern—which describes the field of physical and social relationships which are required to solve the stated problem, in the stated context. This solution is always stated in the form of an instruction—so that you know exactly what you need to do, to build the pattern. Then, after the solution, there is a diagram, which shows the solution in the form of a diagram, with labels to indicate its main components. After the diagram, another three diamonds, to show that the main body of the pattern is finished. And finally, after the diamonds there is a paragraph which ties the pattern to all those smaller patterns in the language, which are needed to complete this pattern, to embellish it, to fill it out.
There are two essential purposes behind this format. First, to present each pattern connected to other patterns, so that you grasp the collection of all 253 patterns as a whole, as a language, within which you can create an infinite variety of combinations. Second, to present the problem and solution of each pattern in such a way that you can judge it for yourself, and modify it, without losing the essence that is central to it.”

This pattern template is an adaptation of this form for wiki. Apart from the use of wiki sections, the only real difference is the added section with examples which we feel is important in our domain. This form is also very much compatible with the form proposed originally by Via Nova Architectura. The difference is in combining the sections ‘Problems’, ‘Forces’ and ‘Tensions’ into a single section. The reason for this is to lower the threshold for novice pattern authors.

The patterns Composite Retrieval Services and Business Process Composition are two examples of descriptions based on this template.

How to use this template?
Just copy the text shown below (between the delimiting lines on this page) into your new page. The sections will be automatically created. Replace the texts in curly braces with your own texts.

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{a short text (two sentences at most) if this pattern, to the best of your knowledge, has been described before - otherwise this paragraph is not present. It specifies only where this description originates from.}

{a drawing showing an archetypal use, preferably from a real-life use. The name of the organization where the shown solution has been implemented should be listed under examples – insert a wiki link to that subsection here}

==Context==
{an introductory paragraph, which sets the context for the pattern. Also explain how your pattern helps to complete certain larger patterns}

==Problem, Forces and Tensions==
{the essence of the problem in one or two sentences}

{the full description of the problem, tensions and forces; the longest section. Describe here the empirical background of the pattern, the evidence for its validity, the range of different ways the pattern can be manifested etc. Describe the forces and tensions. Use drawings and diagrams as appropriate.

After the description where you set the arguments for the solution you can (in style of the Alexander’s pattern) keep the word “therefore”}

Therefore:
==Solution==
{the summary of the solution stated in a few sentences and in the form of an instruction}

{a diagram visualizing the solution}

==Resulting Context and Consequences==
{elaboration on the consequences of the use of this pattern. Use this section to describe the resulting context and explain how to tie this pattern to smaller patterns which are needed to complete it. Elaborate on advantages and disadvantages.}

==Examples==
=== {company name or another reference}===
{more on this example}
=== {company name or another reference}===
{more on this example}

==References==
{* [last name author, year] author(s): Title of the publication, publisher, date of publication, reference number if relevant (ISBN...), url if Internet access possible}

==Date==
The date of the last pattern update, last Writers' Workshop, etc.

[[Category:Enterprise architecture patterns]]

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