PUGH CHART

Design objectives	Weight	Simple fixed-stem lamp	Flexible-neck lamp	Geared hinge lamp (datum)	Servo-actuated LED lamp
Safety,stability	8	0	−	0	−
Ease of adjustment	9	−	0	0	+
Lighting control	7	−	0	0	+
Ease of manufacture	5	+	+	0	−
Cost and maintenance	6	+	+	0	−
Weighted score (+)		11	11	0	16
Weighted score (−)		−9	−8	0	−19
Net total		2	3	0	−3

5.1 Justifications for score given

Design No.	Objective	Score Allocated	Justification for the Score
1	Safety and stability	0	The fixed stem has few moving parts, but its overall safety and stability are considered equivalent to the geared hinge datum.
	Ease of adjustment	-9	The fixed stem provides less positioning flexibility than the adjustable geared hinge lamp.
	Lighting control	-7	It offers fewer options for directing the light than the datum.
	Ease of manufacture	5	Its simple construction is easier to manufacture than a design with gears and articulated joints.
	Cost and maintenance	6	Fewer mechanical parts are expected to reduce cost and maintenance needs.
2	Safety and stability	-8	The flexible neck may bend or droop under the lamp head, making it less stable than the datum.
	Ease of adjustment	0	The neck can be repositioned by hand, making adjustment broadly comparable to the datum.
	Lighting control	0	The user can direct the light by bending the neck, comparable to the datum’s manual positioning.
	Ease of manufacture	5	The flexible neck design avoids the datum’s geared hinge mechanism, simplifying construction.
	Cost and maintenance	6	Its simpler mechanism is expected to cost less and require less maintenance than the datum.
3	Safety and stability	0	Datum reference design.
	Ease of adjustment	0	Datum reference design.
	Lighting control	0	Datum reference design.
	Ease of manufacture	0	Datum reference design.
	Cost and maintenance	0	Datum reference design.
4	Safety and stability	-8	Motors and powered joints add complexity and possible pinch points compared with the manually adjusted datum.
	Ease of adjustment	9	Servo motors can reposition the lamp arm with less manual effort.
	Lighting control	7	Electronic controls can provide additional options for positioning the lamp and controlling its light.
	Ease of manufacture	-5	Motors, wiring, and control electronics make the design more complex to assemble.
	Cost and maintenance	-6	Additional motors and electronics are expected to increase cost and maintenance needs.

5.2 Selected design

5.3 Function clustering

5.4 Interaction between subsystems

Activity 2.2 : Subsystem List

SL. No.	Subsystem
1	Lightining subsystem
2	User intraction
3	Motion Control

Activity 3 : Interaction Details

subsystem 1

Interaction Type	Subsystem 2	Subsystem 3	Interaction Details
Spatial	No	No	No direct physical connection
Data	Yes	No	Receives brightness adjustment commands from the user interaction subsystem
Material	No	No	No material transfer

subsystem 2

Interaction Type	Subsystem 1	Subsystem 3	Interaction Details
Spatial	No	Yes	User controls are physically connected to the lamp's movement mechanism
Data	Yes	Yes	Sends brightness commands to lighting control and movement commands to motion control
Material	No	No	No material transfer

subsystem 3

Interaction Type	Subsystem 1	Subsystem 2	Interaction Details
Spatial	No	No	No direct physical connection between the subsystems
Data	Yes	Yes	Receives movement commands from user interaction and sends position/status information to lighting control
Material	No	No	No material transfer