Environmental Engineering Reference
In-Depth Information
10
ChangeAnalysis
IntroductIon
As.its.name.implies,.this.technique.emphasizes.change..To.solve.a.problem,.one.must.
look.for.deviation.from.the.norm..Change.analysis.follows.a.logical.sequence..It.is.
based. on. the. principle. of. differences. and. considers. problems. to. result. from. some.
unanticipated. change.. An. analysis. of. the. change. is. employed. to. determine. causes.
using.the.following.steps:
.
1.. Deine.the.problem..(What.happened?)
.
2.. Establish.the.norm..(What.should.have.happened?)
.
3.. Identify,.locate,.and.describe.the.change..(What,.where,.when,.to.what.extent?)
.
4.. Specify.what.was.and.what.was.not.affected.
.
5.. Identify.the.distinctive.features.of.the.change.
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6.. List.the.possible.causes.
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7.. Select.the.most.likely.causes.
When to use chAnge AnAlysIs
Change.analysis.is.used.when.the.problem.is.obscure..It.is.a.systematic.process.that.
is.generally.used.for.a.single.occurrence.and.focuses.on.elements.that.have.changed..
It.compares.the.previous.trouble-free.activity.with.the.occurrence.to.identify.differ-
ences..These.differences.are.subsequently.evaluated.to.determine.how.they.contrib-
uted.to.the.occurrence.
hoW to use chAnge AnAlysIs
Change. analysis. looks. at. a. problem. by. analyzing. the. deviation. between. what. is.
expected. and. what. actually. happened.. The. evaluator. essentially. asks. what. differ-
ences. occurred. to. make. the. outcome. of. this. task. or. activity. different. from. all. the.
other. times. this. task. or. activity. was. successfully. completed.. This. technique. con-
sists.of.asking.the.questions:.What?.When?.Where?.Who?.How?.Answering.these.
questions.should.lead.toward.answering.the.root.cause.question:.Why?.Primary.and.
.secondary.questions.included.within.each.category.provide.the.prompting.necessary.
to.thoroughly.answer.the.overall.question..Some.of.the.questions.may.not.be.appli-
cable. to. any. of. the. existing. conditions.. Some. amount. of. redundancy. exists. in. the.
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