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Pietro Terna [email protected] Department of Economics and Finance “G.Prato” University of Torino - Italy Evolving a simulated system of enterprises with jESevol and Swarm web.econ.unito.it/terna web.econ.unito.it/terna/jes. jESevol. _jES->jESlet and jESevol.

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jesevol

Pietro [email protected]

Department of Economics and Finance “G.Prato”

University of Torino - Italy

Evolving a simulated system of enterprises with jESevol and Swarm

web.econ.unito.it/terna

web.econ.unito.it/terna/jes

jESevol

SwarmFest, CSCS, University of Michigan

jes jeslet and jesevol
_jES->jESlet and jESevol

_______________________________________

jES jESlet and jESevol

_______________________________________

SwarmFest, CSCS, University of Michigan

jve jes
jVE->jES

From jES …

java Enterprise Simulator

… to jESlet (with a didactic goal) and …

… to jESevol, to simulate an evolving system of enterprises

SwarmFest, CSCS, University of Michigan

overview
_overview

_______________________________________

Overview

_______________________________________

SwarmFest, CSCS, University of Michigan

overview 1
overview 1

Overview 1/2

From jES (our java Enterprise Simulator), we have derived jESevol, or “Evolutionary java Enterprise Simulator”. jES is a large Swarm-based package[1] aimed at building simulation models both of actual enterprises and of virtual ones. jESevol simulates systems of enterprises or production units in an evolutionary context, where new ones arise continuously and some of the old are dropped out.

Our environment is a social space with metaphorical distances representing trustiness and cooperation among production units (the social capital). The production is represented by a sequence of orders; each order contains a recipe, i.e. the description of the sequence of activities to be done by several units to complete a specific production.

[1] Download last versions of jES, jESlet and jESevol from

http://web.econ.unito.it/terna/jes

SwarmFest, CSCS, University of Michigan

overview 2
overview 2

Overview 2/2

Two units can cooperate in the production process only if they are mutually visible in our social network. Units that do not receive a sufficient quantity of orders, as well as the ones that cannot send the accomplished orders to successive units, disappear.

New enterprises arise, in the attempt of filling the structural holes (Burt, 1992; Walker et al., 1997) of our social network.

A complex structure emerges from our environment, with a difficult and instable equilibrium whenever the social capital is not sufficient.

References

Burt R.S. (1992), Structural Holes – The Social Structure of Competition. Cambridge, MA, Harvard University Press.

Walker G., Kogut B., Shan W. (1997), Social Capital, Structural Holes and the Formation of an Industry Network, in Organization Science. Vol. 8, No. 2, pp.109-25.

SwarmFest, CSCS, University of Michigan

evolving system
evolving system

We look at an incomplete production system continuously adapting itself to the reality coming from the global demand of the market …

… while new firms arise and old ones are dropped off

To produce goods, supply chains are created and modified, according to the changes in exiting firms

SwarmFest, CSCS, University of Michigan

jes basics
_jES basics

_______________________________________

jESbasics

_______________________________________

SwarmFest, CSCS, University of Michigan

wd dw wdw
WD, DW, WDW

Three formalisms

WD side or formalism: What to Do

DW side or formalism:whichisDoingWhat

WDW formalism: When Doing What

SwarmFest, CSCS, University of Michigan

dictionary

A dictionary

dictionary

unit = a productive structure; a unit is able to perform one of the steps required to accomplish an order

order = the object representing a good to be produced; an order contains technical information (the recipe describing the production steps)

recipe = a sequence of steps to be executed to produce a good

SwarmFest, CSCS, University of Michigan

a flexible scheme
_A flexible scheme

_______________________________________

A flexible scheme in jESevol

_______________________________________

SwarmFest, CSCS, University of Michigan

dw a flexible scheme
DW: a flexible scheme

DW

Units …

2

1

3

1

4

… on a toroidal space

2

1

Each unit is able to do a specific step …

5

(left and right borders and top and bottom ones are close together)

3

SwarmFest, CSCS, University of Michigan

wd recipes
WD: recipes

WD

… of a recipe

with the recipes of the orders (what to do) expressed as sequences of numbers; orders with recipes are randomly generated with different lengths and structures

1 3 2 4

5 3

4 3 5 1 1

SwarmFest, CSCS, University of Michigan

moving recipes
moving recipes

DW and WD

moving around among units

2

13 2 4

1

3

1

132 4

4

2

1 324

how to choose

?

1

1 3 24

5

3

lack of visibility

Visibility is a metaphorical representation of trustiness and cooperation in a social network; when global visibility increases, we have more “social capital”

SwarmFest, CSCS, University of Michigan

visibility and
visibility and …

Visibility increases with the time (initial visibility is randomly chosen)

  • new units appear randomly (enterprise creation)
  • with strategic relationships …
  • … or alone

visibility changes

some units are dropped out

SwarmFest, CSCS, University of Michigan

slide16
… bars

The left (blue) bar of each unit reports the number of waiting orders (do be done)

The right (red) bar of each unit reports the number of unsent products, due to the fact that a unit able to do the required step does not exist or is not visible

The down bar of each unit reports the number of consecutive clock ticks in which the unit has been idle

If >maxInactivity the unit is dropped out and all unsent products are lost

If >maxUnsentProducts the unit is dropped out and all unsent and waiting products are lost

SwarmFest, CSCS, University of Michigan

an introductory case
_an introductory case

_______________________________________

An introductory case, robust and fragile

_______________________________________

SwarmFest, CSCS, University of Michigan

the parameters robust introductory case

Introductory robust case

the parameters, robust introductory case

potentialUnitTypes 5

unitGenerationInitialP 1

potentialUnitNumberPerType 2

newUnitGenerationP 0.0

interVisibilityMinLevel 0

increasingVisibilityStep 0.0

maxInactivity 10

maxUnsentProducts 10

max n. of types and max presence per type, here 5 * 2 with p=1

p of a new unit in each cycle, with a random type

in this basic case all units are visible and visibility does not change

we assume that an actual firm is dropped out from the market after three months of inactivity, so 10 ticks = 3 months of history

Why 10? Our recipes have here maxStepNumber =5 and maxStepLength=2; potentially, in 10 ticks, each unit can receive an order, but only as a limit case; with this parameters the system can be exposed to a complete crash

similarly …

SwarmFest, CSCS, University of Michigan

introductory case robust case
introductory case: robust case

Introductory robust case

only 5 units kept alive

1,000 ticks = 25 years of actual time

PRODUCTION

global/potential

final/potential

final/global

SwarmFest, CSCS, University of Michigan

the parameters fragile introductory case

Introductory fragile case

the parameters, fragile introductory case

potentialUnitTypes 10

unitGenerationInitialP 1

potentialUnitNumberPerType 1

newUnitGenerationP 0.0

interVisibilityMinLevel 0

increasingVisibilityStep 0.0

maxInactivity 10

maxUnsentProducts 10

max n. of types and max presence per type, here 10 * 1 with p=1

Our recipes have here

maxStepNumber 10 and

maxStepLength 1

SwarmFest, CSCS, University of Michigan

introductory case fragile case
introductory case: fragile case

Basic fragile case

no units kept alive

150 ticks < 4 years of actual time

PRODUCTION

global/potential

final/potential

final/global

SwarmFest, CSCS, University of Michigan

a study case
_a study case

__________________________________________________

A study case, with 3 versions:

(i) basic,

(ii) increasing social capital,

(iii) with greater financial intervention of the banking system

__________________________________________________

SwarmFest, CSCS, University of Michigan

the parameters basic study case

(i) basic study case, starter file 5 in jESevol 0.3.00

the parameters, basic study case

potentialUnitTypes 5

unitGenerationInitialP 0.8

potentialUnitNumberPerType 2

newUnitGenerationP 0.8

interVisibilityMinLevel 1

increasingVisibilityStep 5

maxInactivity 10

maxUnsentProducts 10

max n. of types and max presence per type, here 5 * 2 with p=0.8

p of a new unit in each cycle, with a random type

in this study case, min visibility is 1, i.e. at least one common patch; visibility increases of 5 patches in each tick

Our recipes have here

maxStepNumber 5 and

maxStepLength 2

SwarmFest, CSCS, University of Michigan

study case basic
study case: basic

(i) basic study case, starter file 5 in jESevol 0.3.00

a relevant variability in the number of units (social costs), with the trace of a cycle

a medium performance in term of potential production

1,000 ticks = 25 years of actual time

PRODUCTION

global/potential

final/potential

final/global

some form of structure seems to emerge

SwarmFest, CSCS, University of Michigan

the parameters increasing social capital study case

(ii) Increasing social capital study case, starter file 5.2 in jESevol 0.3.00

the parameters, increasing social capital study case

potentialUnitTypes 5

unitGenerationInitialP 0.8

potentialUnitNumberPerType 2

newUnitGenerationP 0.8

interVisibilityMinLevel 1

increasingVisibilityStep 10

maxInactivity 10

maxUnsentProducts 10

max n. of types and max presence per type, here 5 * 2 with p=0.8

p of a new unit in each cycle, with a random type

in this study case, min visibility is 1, i.e. at least one common patch; visibility increases of 10 patches in each tick

Our recipes have here

maxStepNumber 5 and

maxStepLength 2

SwarmFest, CSCS, University of Michigan

study case increasing social capital
study case: increasing social capital

(ii) Increasing social capital study case, starter file 5.2 in jESevol 0.3.00

a relevant variability in the number of units (social costs), but now with an evident cycle

a good (and increasing) performance in term of potential production

1,000 ticks = 25 years of actual time

PRODUCTION

global/potential

final/potential

final/global

evident structures emerge

SwarmFest, CSCS, University of Michigan

the parameters bank system study case

(iii) Greater financial intervention of the banking system study case,starter file 5.3 in jESevol 0.3.00

the parameters, bank system study case

potentialUnitTypes 5

unitGenerationInitialP 0.8

potentialUnitNumberPerType 2

newUnitGenerationP 0.8

interVisibilityMinLevel 1

increasingVisibilityStep 5

maxInactivity 15

maxUnsentProducts 10

in this study case, min visibility is 1, i.e. at least one common patch; visibility is increases of 5 patches in each tick

we assume that an actual firm is dropped out from the market after 15 ticks of inactivity, instead of 10

Our recipes have here

maxStepNumber 5 and

maxStepLength 2

SwarmFest, CSCS, University of Michigan

study case bank system study case
study case: bank system study case

(iii) Greater financial intervention of the banking system study case,starter file 5.3 in jESevol 0.3.00

a less relevant variability in the number of units (reduced social cost)s, always with an evident cycle

a good performance in term of potential production

1,000 ticks = 25 years of actual time

PRODUCTION

global/potential

final/potential

final/global

evident structures emerge

SwarmFest, CSCS, University of Michigan

stability perspectives

Stability

Cases i, ii and iii are stable also running them for 4,000 ticks (one century)!

Stability; perspectives

Short term enhancements

A lot of investigation is necessary on cases (i), (ii) and (iii) modelling explicitly the banking system, with the concurrent effects of the cases of bankruptcy in firms and banks

Using a Genetic Algorithm tool to choose units to be created at each tick and where to place them; the fitness will be generated by jESevol itself, from different points of view: the whole economic system, a specific unit, a cluster of units, …

SwarmFest, CSCS, University of Michigan

address again
address again

Let run case 5.2 or 5.3 at the question time!

[email protected]

web.econ.unito.it/terna

web.econ.unito.it/terna/jes

SwarmFest, CSCS, University of Michigan

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