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Hazop Study MethodologyImportant terms pertaining to the study are:

Intention: The intention defines how the part is expected to operate. This can take a number 

of forms and can be either descriptie or diagrammatic. In many cases it will be a flow sheet

or line diagram.

Deviations: These are departure from the intension which are discoered by systematically

applying the guide words.

Causes: These are the reasons why deiations might occur. !nce a deiation has been shownto hae a conceiable or realistic cause" it can be treated as meaningful.

Consequences: These are the results of the deiations.

Hazards: These are conse#uences which can cause damage" in$ury or loss.

Guide Words: These are simple words which are used to #ualify the intention in order toguide and stimulate the creatie thinking process and so discoer deiations. % list of guide

words is gien in table below:

Guide

Words

Meanings Comments

 &! or &!TThe complete negation of 

these intentions &o part of the intentions is achieed by

nothing else happensM!'(

)uantitatie increases or decreases

These refer to #uantities * properties such as

flow rates and temperatures as well as

actiities like +H(%T, and +'(%-T,(SS

%S /(%S

% #ualitatie increase%ll the design and operating intentions are

achieed together with some additionalactiity

0%'T !1 % #ualitatie decrease!nly some of the intensions are achieed2

some are not'(3('S(

The logical opposite of 

the intention

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This is mostly applicable to actiities" for example reerse flow or chemical reaction. It

can also be applied to substances" e.g.+0!IS!&, instead of +%&TI4!T(, or +4,

instead of +, optical isomers

!TH(' 

TH%&-omplete substitution

 &o part of the original intention is achieed.Something #uite different happens.

2. Team Composition:

Hazard and !perability Studies are normally carried out by multi5disciplinary teams. The

examination re#uires the team to hae a detailed knowledge of the way the plant is intendedto work. This re#uires both concerned with the design of the plant and those concerned with

its operation.

3. The rocedure !or a stud":

The principles described in the preious section are put into practice in a procedure which

consists of the following steps:6. 4efine ob$ecties and scope

7. Select the team

8. 0repare for the study9. -arry out the examination

. 'ecord the results;. 1ollow up actions