The basic database model consists of objects that may have properties and may be interconnected by means of relationships. The types of object and relationship are predefined within PSL, there being more than 20 kinds of object and more than 50 kinds of relationship. The objects and relationships are concerned with various aspects of the system for which requirements are being expressed: system input/output flow, system structure, data structure, data derivation, system size and volume, system dynamics, system properties, and project management. PSA permits the analysis of the database and the production of various kinds of report, e.g. on database modifications, database content, and on unused data objects or breaks in information flow.
PSL/PSA was developed by Daniel Teichroew on the ISDOS project at the University of Michigan. The system has been implemented on a wide range of computers and has been used extensively by many organizations.
"PSL/PSA." A Dictionary of Computing. . Encyclopedia.com. (March 23, 2018). http://www.encyclopedia.com/computing/dictionaries-thesauruses-pictures-and-press-releases/pslpsa
"PSL/PSA." A Dictionary of Computing. . Retrieved March 23, 2018 from Encyclopedia.com: http://www.encyclopedia.com/computing/dictionaries-thesauruses-pictures-and-press-releases/pslpsa
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"PSL/PSA." The Oxford Dictionary of Abbreviations. . Encyclopedia.com. (March 23, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/pslpsa
"PSL/PSA." The Oxford Dictionary of Abbreviations. . Retrieved March 23, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/pslpsa