Value Analysis Model is authored by James Comb, who believes that in value criteria values are ascribed to a given class of conditions For example, it is wrong to speak lies, kill, or cheat etc. but the same value criterion may not apply in all circumstances. For example deceiving others may be right when it is a question of saving a life or when larger interests of a country (like its security) are at stake. Hence a value criterion may not be equally valid in all the circumstances, all the time.

Comb postulates that value criteria give positive or negative "valences" to facts. He has cited the example of euthanasia (mercy killing). It is accepted that 'killing it wrong'. This attaches a negative valence to the fact that euthanasia involves ; killing. Here a negative evaluation of the act of euthanasia is involved hence decision becomes difficult. The evaluation need to balance the positive and negative facts, before taking