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Functional Requirements
Functional Requirements
FR1: Control the flowof water (Q)
FR2: Control water temperature (T)
FR1: Control the flowof water (Q)
FR2: Control water temperature (T)
Design Parameters
Design Parameters
DP1: Opening Angle of value 1, Q1
DP2: Opening Angle of value 2, Q2
DP1: Handle Fitting
DP2: handle moving sideway
Hot water
Cold water
Hot water
Cold water
Q1
Q2
Q2
Q2
Completed Design
(
DPs
create conficiting functions)
Uncompleted Design
(
CPs
maintain independence of functions)
DP1
DP2
DP1
DP2
x
x
xx
x
0
0x
Control Flow
Control Flow
Control Temperature
Control Temperature
(a)
(b)
FIGURE 13.3
Faucet coupling example.
In general, the mapping process can be written mathematically as the following
matrix equations:
⎧
⎨
⎫
⎬
⎡
⎤
⎧
⎨
⎫
⎬
FR
1
.
.
FR
m
X
0
.
0
DP
1
.
.
DP
m
⎣
⎦
0
X
.
=
.
.
0
⎩
⎭
⎩
⎭
(13.1)
0
.
0
X
mxp
(Uncoupled design)
⎧
⎨
⎫
⎬
⎧
⎨
⎫
⎬
⎡
⎣
⎤
⎦
mxp
FR
1
.
.
FR
m
X
0
.
0
DP
1
.
.
DP
m
XX
0
.
=
⎩
⎭
.
.
.
0
⎩
⎭
(13.2)
.
XX
X
(Decoupled design)
⎧
⎨
⎫
⎬
⎧
⎨
⎫
⎬
⎡
⎤
DP
1
.
.
FR
1
.
.
FR
m
XX
.
X
⎣
⎦
XX
.
=
.
.
X
⎩
⎭
⎩
⎭
(13.3)
X
.
XX
DP
p
mxp
(Coupled design)
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