Essential Systems Analysis

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Essential Systems Analysis was a new methodology for software specification published in 1984 by Stephen M. McMenamin and John F. Palmer for performing Structured Systems Analysis based on the concept of Event Partitioning.[1]

The Essence of a system is "its required behavior independent of the technology used to implement the system".[2] It is a model of what the system must do saying ideally nothing about how it will do it.[2]

The methodology[1] proposed that finding the true requirements for an information system entails the development of an Essential Model for the system, based on the concepts of a perfect internal technology, composed of:

  • a perfect memory, that is infinitely fast and big, and
  • a perfect processor, that is infinitely potent and fast.

It was later adapted by Edward Yourdon to develop Modern Structured Analysis.[3]

The main result was a new and more systematic way to develop the Data Flow Diagrams, which are the most characteristic tool of Structured analysis|Structured Analysis.

Essential Analysis, as adopted in Yourdon´s Modern Structured Analysis, was the main software development methodoly until Object Oriented Analysis became mainstream.


  1. ^ a b McMenamin, Stephen M.; Palmer, John F. (1984). Essential systems analysis. Yourdon Press. ISBN 978-0-917072-30-7.
  2. ^ a b Yourdon, Edward (2006). Just enough structured analysis. Ed Yourdon.
  3. ^ Yourdon, Edward. (1989). Modern structured analysis. Englewood Cliffs, N.J.: Yourdon Press. ISBN 0-13-598624-9. OCLC 17877629.

Edited: 2021-06-18 19:19:22