TASK ALLOCATION IN A TASK ALLOCATION IN A PRODUCTION CHAIN - - PowerPoint PPT Presentation

TASK ALLOCATION IN A TASK ALLOCATION IN A PRODUCTION CHAIN PRODUCTION CHAIN

Swarm Swarm intelligence intelligence project project

Yann Yann Christinat Christinat Matteo Thomas DeGiacomi Matteo Thomas DeGiacomi

Description Description of

• f the

the problem problem

• A

A truck truck assembly assembly chain chain produces produces n n truck truck/ /hour hour

• A

A set set of

• f paint

paint booths booths has to has to color color every every truck truck in a in a predetermined predetermined color color c c

• Every

Every booth booth is is charged charged with with one

• ne color

color

• Every

Every booth booth needs needs t1 t1 minutes minutes to to paint paint a a truck truck

• A

A booth booth can can change change color color t2 t2 minutes minutes

• If

If a a truck truck can can‘ ‘t t be be handled handled, , it it‘ ‘s s considered considered as lost as lost

GOAL: GOAL: assign assign the the trucks trucks to to the the paint paint booths booths as as efficiently efficiently as as possible possible

Booth Booth state state machine machine

Changing color Working Waiting

Task completed New task, color matching New task, color mismatch Color changed

Involved Involved parameters parameters

• Environment

Environment parameters parameters: : describe describe the the environment environment ( (throughput throughput of

• f

the the assembly assembly chain chain, time , time needed needed by by a a booth booth to to change change a a color color or

• r perform

perform a a task task). ).

• Allocation

Allocation parameters parameters: : define define the the way way allocation allocation is is performed performed. . Depend Depend on

• n adopted

adopted strategy strategy. .

The The Market Market-

• based

based approach approach

• Booth

Booth bid bid for for the the trucks trucks. . Assigned Assigned trucks trucks are are put put in a in a queue queue in front of in front of the the winner winner. .

• Bidding

Bidding function function: : b bi

i =

= α αq qi

i+

+β βm mi

i

( (q qi

i :

: queue queue length length, , m mi

iε

ε{0,1}

{0,1} color color matching matching) )

• An

An auctioner auctioner selects selects the the winner winner

• Global

Global objective

• bjective function

function: : T(t T(t) = ) = min( min(b bi

i(t

(t)) ))

Enhancing Enhancing specialisation specialisation

• If

If more more than than a a winner winner is is found found: : Select Select the the one

• ne with

with the the color color of

• f the

the last last truck truck in in queue queue matching matching the the one

• ne of
• f the

the current current truck truck. .

• If

If still still more more than than one

• ne truck

truck is is found found: : random random selection selection

The The Threshold Threshold-

• based

based approach approach

• New

New trucks trucks are are put put in a in a set set ( (environment environment) )

• The

The quantity quantity of

• f trucks

trucks of a

• f a given

given color color c c in in the the environment environment represent represent the the stimulus[c stimulus[c] ]

• booths

booths have have a a threshold[c threshold[c] ] for for every every color color

• A

A booth booth activates activates if if threshold[c] < stimulus[c]

The distance booth-truck depends on the

color (0 if match, 1 if mismatch)

Dynamic Dynamic threshold threshold

• Prize

Prize for for a a booth booth receiving receiving a a task task and and already already having having the the right right color color c: c: lower lower threshold[c threshold[c] ( ] (-

• 1)

1)

• If

If a a prize prize is is given given, a , a penalty penalty is is assigned assigned to to a a randomly randomly selected selected booth booth: : higher higher threshold[c threshold[c] (+1) ] (+1) IDEA: IDEA: enhancing enhancing specialisation specialisation. .

Market Market-

• based

based parameters parameters

• Best

Best performances performances for for the the market market based based approach approach: : α α=0.2, =0.2, β β=1.0 =1.0

In In successive successive benchmarks benchmarks we we used used those those values values

Market Market-

• based

based performances performances

Threshold Threshold-

• based

based performances performances

Conclusions Conclusions

• Market

Market-

• based

based: : balanced balanced workload workload on

• n each

each booth booth, , equal equal quantity quantity of

• f change

change color color. .

• Threshold

Threshold-

• based

based: : unbalanced unbalanced workload workload, , working working booths booths change change color color less less often

• ften.

. Globally Globally threshold threshold-

• based

based performs performs better better! !

References References

• Campos

Campos, , Mike Mike; ; Bonabeu Bonabeu, , Eric Eric; ; Th Thé éradulaz radulaz, , Guy Guy; ; Denembourg Denembourg, , Jean Jean-

• Louis

Louis. . Dynamic Dynamic Scheduling Scheduling and and Division Division of

• f

Labor Labor in Social in Social Insects Insects. . Adaptative Adaptative Behavior Behavior 2001, pag 2001, pag.83 .83-

• 92

92

QUESTIONS? QUESTIONS?