Effects of Plan Splitting

I used the Fixit domain for this analysis. From a quick analysis of the facts file, we can see that there are exactly three facts which differ from the initial description to the final description:
InitialFinal
(not-inflated wheel2)(inflated wheel2)
(in wheel2 boot)(on wheel2 the-hub)
(on wheel1 the-hub)(in wheel1 boot)
This gives us 6 possible mid-points to investigate:
Mid-pointPut W1 in bootInflate W2, Put W2 on Hub
A
open_boot
fetch_jack_boot
fetch_wrench_boot
loosen_nuts_the-hub
jack-up_the-hub
undo_nuts_the-hub
remove-wheel_wheel1_the-hub
put-away_wheel1_boot
fetch_pump_boot
fetch_wheel2_boot
inflate_wheel2
put-on-wheel_wheel2_the-hub
put-away_pump_boot
do-up_nuts_the-hub
jack-down_the-hub
tighten_nuts_the-hub
put-away_jack_boot
put-away_wrench_boot
close_boot
Mid-pointInflate W2Put W2 on Hub, Put W1 in Boot
B
open_boot
fetch_pump_boot
inflate_wheel2
fetch_jack_boot
fetch_wrench_boot
put-away_pump_boot
loosen_nuts_the-hub
jack-up_the-hub
undo_nuts_the-hub
remove-wheel_wheel1_the-hub
put-on-wheel_wheel2_the-hub
put-away_wheel1_boot
do-up_nuts_the-hub
jack-down_the-hub
tighten_nuts_the-hub
put-away_jack_boot
put-away_wrench_boot
close_boot
Mid-pointPut W2 on HubInflate W2, Put W1 in boot
C
open_boot
fetch_jack_boot
fetch_wrench_boot
fetch_wheel2_boot
loosen_nuts_the-hub
jack-up_the-hub
undo_nuts_the-hub
remove-wheel_wheel1_the-hub
put-on-wheel_wheel2_the-hub
fetch_pump_boot
remove-wheel_wheel2_the-hub
put-away_wheel1_boot
inflate_wheel2
put-on-wheel_wheel2_the-hub
put-away_pump_boot
do-up_nuts_the-hub
jack-down_the-hub
tighten_nuts_the-hub
put-away_jack_boot
put-away_wrench_boot
close_boot
Mid-pointInflate W2, put on hubPut W1 in boot
D
open_boot
fetch_jack_boot
fetch_pump_boot
fetch_wrench_boot
fetch_wheel2_boot
loosen_nuts_the-hub
inflate_wheel2
jack-up_the-hub
undo_nuts_the-hub
remove-wheel_wheel1_the-hub
put-on-wheel_wheel2_the-hub
put-away_pump_boot
do-up_nuts_the-hub
put-away_wheel1_boot
jack-down_the-hub
tighten_nuts_the-hub
put-away_jack_boot
put-away_wrench_boot
close_boot
Mid-pointW2 inflated, W1 in bootW2 on hub
E
open_boot
fetch_jack_boot
fetch_pump_boot
fetch_wrench_boot
fetch_wheel2_boot
loosen_nuts_the-hub
inflate_wheel2
jack-up_the-hub
undo_nuts_the-hub
remove-wheel_wheel1_the-hub
put-away_wheel1_boot
put-on-wheel_wheel2_the-hub
put-away_pump_boot
do-up_nuts_the-hub
jack-down_the-hub
tighten_nuts_the-hub
put-away_jack_boot
put-away_wrench_boot
close_boot
Mid-pointW2 on Hub, W1 in BootW2 Inflated
F
open_boot
fetch_jack_boot
fetch_wrench_boot
fetch_wheel2_boot
loosen_nuts_the-hub
jack-up_the-hub
undo_nuts_the-hub
remove-wheel_wheel1_the-hub
put-on-wheel_wheel2_the-hub
put-away_wheel1_boot
fetch_pump_boot
remove-wheel_wheel2_the-hub
inflate_wheel2
put-on-wheel_wheel2_the-hub
put-away_pump_boot
do-up_nuts_the-hub
jack-down_the-hub
tighten_nuts_the-hub
put-away_jack_boot
put-away_wrench_boot
close_boot
Looking at each of these shows the following results:
CaseFirst Half LengthSecond Half LengthReduction Factor
A8111.4EE09
B3162.7EE03
C9121.0EE08
D1181.4EE09
E1181.4EE09
F10111.3EE09

From this it is clear that even in the worst case, Case B with only a search space reduction of 2744, we could easily explore all these possible sub-plans still do less computation than the single plan.


Return to Planning Models
jpg3u@virginia.edu
Last modified: Wed Jan 31 15:03:30 2001