OR notes

Trying to understand and predict reality is one of humanity’s dreams. Nevertheless, reality is sometimes complex (see note 1), and it is therefore difficult to understand all of it with a single model. Hence, we must divide reality into different pieces that can be interpreted and obtain a partial explanation of the target. As a result, different scientific disciplines have been created to try to explain different phenomena using various models and, if possible, predict the behavior of the target subsystem.

Operations Research (see note 2) (OR) uses a set of methodologies to construct models to represent the reality to try to understand and anticipate some of the system problems. Models are tools for conceptualizing reality. Therefore, they simplify system compression and analysis. Computers were the main tool that allowed OR to develop. Many of the methods require large amounts of calculations, which in most cases are repetitive. With the help of computers, the quantity and quality of the problems solved by OR grew, which expanded the use of the discipline.
In applying these new methodologies, the relationships between different system elements are reproduced and a set of simplification hypotheses can be used (see note 3).


  1. Some authors remarks that sometimes, complex behaviors are based in very simple rules: "(...) whenever a phenomenon is encountered that seems complex it is taken almost for granted that the phenomenon must be the result of some underlying mechanism that is itself complex. But my discovery that simple programs can produce great complexity makes it clear that this is not in fact correct." (Wolfram 2002). In the other hand, other authors reviewing that book (Kurzweil 2002) remark that reality is more complex that Wolfram suggest “The order of complexity of a human is greater than the interesting but ultimately repetitive (albeit random) patterns of a Class 4 automaton”. Anyway, we do not want to enter in the discussion about if the reality, or the perception of this reality, is complex or not, only to note that for us sometimes this reality is very complex.
  2. Operations research is traditionally considered to have emerged in the military during World War II. The initial goal of this research was to optimize military resources during the conflict. The discipline development can be said to have begun as early as the beginning of the industrial revolution. Due to the growing complexity of the organizations that replaced traditional craftspeople, new problems appeared, such as production planning problems. These problems allowed this new discipline to develop.
  3. Simplification hypotheses are not true in the system but are used in the construction of the model to simplify the modeling process (and sometimes just to make this process possible, due to the inherent complexity of the system).


Kurzweil, Ray. 2002, Reflections on Stepehn Wolfram’s ‘A New Kind of Science’ , http://www.kurzweilai.net/articles/art0464.html?printable=1 (accessed 4 January 2007)

Wolfram, Stephen 2002, A new Kind of Science, Wolfram Media, Inc.

Pau Fonseca i Casas
Department of Statistics and Operations Research

Universitat Politècnica de Catalunya - BarcelonaTECH
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