7/25/2019 Unit 04 Assessment Feedback

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Unit 4 Assessment Instructor Feedback and Follow-up

Describing the functions of a device or system can be a challenge, whether the

device is simple, such as an IV tube clip, or complicated like a power washer. In

reviewing your submissions it looks like most of you understand how to analyze the

functions of a device; however, there was some confusion about the dierences

between basic and secondary functions as well as how to generate performance

specications. !ere are some things to keep in mind when you apply functional

analysis in the future.

"asic functions answer the #uestion $what does it do%& and include $pumps water,&

$sprays high pressure water& and $allows operator to control 'ow and direction.&

(hink of the power washer as a black bo) with all the functions either 'owing in or

out* inputs + low pressure water, user controls, energy; outputs + high pressurewater, noise, heat. nd be careful not to confuse basic functions with ob-ectives,

such as $should be portable& or secondary functions.

e#uired secondary functions answer the more complicated #uestion $in order to

spray high pressure water, what else has to happen%& /ome of the answers we

came up with include $consume energy& and $generate noise.& 0nwanted

secondary functions focussed on safety issues and included $high pressure water

in-ures operator.& nd remember to be descriptive and detailed when you generate

your functions + $wash cars, clean houses, decontaminate workspaces& are too

general and application specic to be good functions.

1erformance re#uirements are the numbers that tell us how well a function is being

performed. (hey should be specic, referring to one of the basic functions, and

include a number if at all possible. !ow well the basic function $pumps water& is

performed could be measured against the performance re#uirement $must pump

23 litres per minute at 24 k1a pressure.& 5ou will note that the word $must&

appears in each performance re#uirement, along with a numerical value that

#uanties the performance. nd try to be reasonable when you select your

re#uirements + a little research and rough calculations can be helpful in nding

suitable values for your specications.

1rofessor cheson and 1rofessor (eertstra