Samrachna is Structure, which is long-lasting and needs a revolution for change. Tribal structure, Feudal Structure, capitalist structure, parliamentary structure, democratic structure, autocratic structure, dictatorship of the proletarait, socialism, etc., as far as the the society is concerned. Structure also can apply to smaller things, e.g., the anatomy of a human being.
vyavastha i.e Arrangement is a temporary thing, expedient with the time, that keeps on changing qickly. For example, the salary
of the staff you employ, the arrangement of police and army to crush insurgency at some place, the government of Iraq sprung upon the ruins of Iraq, the arrangement of anarchy and self-righteousness in USA and UK, the impotence, blindness, dumbness, etc., of the International Courts and their judges and advocates about the hundreds of thousands of murders that Bush and Company stages in Iraq, and so forth.

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Note added at 4 hrs (2008-02-16 23:11:11 GMT)
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Structure is the same thing as system in sociology.
There are two sociological theories, Structuralism and Structural Functionalism that view the culture of any place/country from the narrow and pathetically backward capitalist point of view, as Bush, Tony and Company view justice.

संरचना और व्यवस्था means the Structure and Setup of an Organization

In the given context the words sangrachna and vyavastha(used together) means the parts or elements of which something is made(composition) AND the way in which something is organized, built or put together(structure), respectively. I have picked both these meanings from Oxford Advanced Learner’s Dictionary which is in paper form with me. Please also see the following links:

composition Show phonetics
noun [U]
the parts, substances, etc. that something is made of:
the composition of the atmosphere

(from Cambridge Advanced Learner's Dictionary)
http://dictionary.cambridge.org/define.asp?key=15711&dict=CA...

structure (ARRANGEMENT) Show phonetics
noun [C or U]
the way in which the parts of a system or object are arranged or organized, or a system arranged in this way:
the grammatical structure of a sentence
The structure of this protein is particularly complex.
They have a very old-fashioned management structure.
Some people like the sense of structure that a military lifestyle imposes.
http://dictionary.cambridge.org/define.asp?key=79050&dict=CA...


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Note added at 11 hrs (2008-02-17 06:48:52 GMT)
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I also believe that the Hindi word संरचना shouldn't be used with व्यवस्था as they are same(structure or arrangement). Instead of संरचना और व्यवस्था it could be संघटन(constitution) और व्यवस्था.