Package 'Inventorymodel'

Title: Inventory Models
Description: Determination of the optimal policy in inventory problems from a game-theoretic perspective.
Authors: Alejandro Saavedra Nieves
Maintainer: Alejandro Saavedra Nieves <[email protected]>
License: GPL-2
Version: 1.1.0.1
Built: 2024-11-06 06:23:31 UTC
Source: CRAN

Help Index


Coalitions

Description

Possible coalitions with n players.

Usage

coalitions(n)

Arguments

n

Number of players

Value

This function gives the coalitions in a binary mode and usual way.

Examples

coalitions(3)
#$Binary
#     [,1] [,2] [,3]
#[1,]    0    0    0
#[2,]    1    0    0
#[3,]    0    1    0
#[4,]    0    0    1
#[5,]    1    1    0
#[6,]    1    0    1
#[7,]    0    1    1
#[8,]    1    1    1
#
#$Classic
#[1] "0"   "'{ 1 }'" "'{ 2 }'" "'{ 3 }'" "'{ 1,2 }'" "'{ 1,3 }'" "'{ 2,3 }'"  
#[8] "'{ 1,2,3 }'"

EOQ

Description

This function obtains the optimal orders and the associated cost in the EOQ model.

Usage

EOQ(n = NA, a = NA, d = NA, h = NA, m = NA)

Arguments

n

Number of agents in the inventory model.

a

The fixed cost per order.

d

Vector. Deterministic demands per time unit to each agent.

h

Vector. Holding costs to each agent.

m

Vector. Number of orders to each agent (optional).

Value

This function calculates two vectors. The first shows the optimal order for each agent. The second vector indicates the associated cost to these orders.

Examples

EOQ(n=3,a=600,d=c(500,300,400),h=c(9.6,11,10))

#EOQ model
#$"Optimal order"
#[1] 250.0000 180.9068 219.0890
#
#$"Order costs"
#[1] 2400.000 1989.975 2190.890

EOQcoo

Description

This function obtains the optimal orders and the associated cost when agents are cooperating in the EOQ model.

Usage

EOQcoo(n = NA, a = NA, d = NA, h = NA, m = NA)

Arguments

n

Number of agents in the inventory model.

a

The fixed cost per order.

d

Vector. Deterministic demands per time unit to each agent.

h

Vector. Holding costs to each agent.

m

Vector. Number of orders to each agent (optional).

Value

A list with the following components:

  • Optimal order If n is lesser than 0, a matrix with all possible coalitions in the first column. The next n columns contain the associated cost to each agent in the coalition. Last column indicates the global cost of the optimal order. Otherwise, this matriz contains the individual costs and the associated values for N.

Examples

EOQcoo(n=3,a=600,d=c(500,300,400),h=c(9.6,11,10))

#EOQ model
#Cooperative case
#Optimal order
#    Coalition        1        2        3 Coalitional costs
#1           0   0.0000   0.0000   0.0000             0.000
#2     '{ 1 }' 250.0000   0.0000   0.0000          2400.000
#3     '{ 2 }'   0.0000 180.9068   0.0000          1989.975
#4     '{ 3 }'   0.0000   0.0000 219.0890          2190.890
#5   '{ 1,2 }' 192.4501 115.4701   0.0000          3117.691
#6   '{ 1,3 }' 184.6372   0.0000 147.7098          3249.615
#7   '{ 2,3 }'   0.0000 121.6327 162.1770          2959.730
#8 '{ 1,2,3 }' 157.4592  94.4755 125.9673          3810.512

EPQ

Description

This function obtains the optimal orders and the associated cost in the EPQ model.

Usage

EPQ(n = NA, a = NA, d = NA, h = NA, m = NA, r = NA, b = NA)

Arguments

n

Number of agents in the inventory model.

a

The fixed cost per order.

d

Vector. Deterministic demands per time unit to each agent.

h

Vector. Holding costs to each agent.

m

Vector. Number of orders to each agent (optional).

r

Vector. Replacement rate to each agent. In general, r>d.

b

Vector. Cost of a shortage to each agent.

Value

This function calculates two vectors. The first one shows the optimal order for each agent. The second vector indicates the associated cost to these orders.

Examples

EPQ(n=3,a=600,d=c(500,300,400),h=c(9.6,11,10),m=NA,r=rep(600,3),b=c(100,150,200))
#EPQ model
#$"Optimal order"
#[1] 641.0928 265.0557 388.8444
#
#$"Optimal shortages"
#[1] 9.359019 9.054699 6.172134
#
#$"Order costs"
#[1]  935.9019 1358.2049 1234.4268

EPQcoo

Description

This function obtains the optimal orders and the associated cost when agents are cooperating in the EPQ model.

Usage

EPQcoo(n = NA, a = NA, d = NA, h = NA, m = NA, r = NA, b = NA)

Arguments

n

Number of agents in the inventory model.

a

The fixed cost per order.

d

Vector. Deterministic demands per time unit to each agent.

h

Vector. Holding costs to each agent.

m

Vector. Number of orders to each agent (optional).

r

Vector. Replacement rate to each agent. In general, r>d.

b

Vector. Cost of a shortage to each agent.

Value

A list with the following components:

  • Optimal order If n is lesser than 0, a matrix with all possible coalitions in the first column. The next n columns contain the associated cost to each agent in the coalition. Last column indicates the global cost of the optimal order. Otherwise, this matriz contains the individual costs and the associated values for N.

  • Optimal shortages A matrix, for each coalition (row), contains in the column i the allowed optimal shortages.

Examples

EPQcoo(n=3,a=600,d=c(500,300,400),h=c(9.6,11,10),r=rep(600,3),b=c(100,150,200))

#EPQ model
#Cooperative case
#$`Optimal order
#        1        2        3     Costs
#   0.0000   0.0000   0.0000    0.0000
# 641.0928   0.0000   0.0000  935.9019
#   0.0000 265.0557   0.0000 1358.2049
#   0.0000   0.0000 388.8444 1234.4268
# 363.7611 218.2567   0.0000 1649.4341
# 387.3208   0.0000 309.8566 1549.1036
#   0.0000 196.1473 261.5297 1835.3556
# 291.2332 174.7399 232.9866 2060.2045
#
#$`Optimal shortages`
#        1        2        3
# 0.000000 0.000000 0.000000
# 9.359019 0.000000 0.000000
# 0.000000 9.054699 0.000000
# 0.000000 0.000000 6.172134
# 5.310381 7.455973 0.000000
# 5.654318 0.000000 4.918359
# 0.000000 6.700683 4.151265
# 4.251580 5.969377 3.698200

Inventory Models

Description

This package allows the determination of the optimal policy in terms of the number of orders to apply in the most common inventory problems. Moreover, game-theoretic procedures to share the costs of these situations have been considered by proposing allocations for the involved agents.

Details

Package: Inventorymodel
Type: Package
Version: 1.0
Date: 2017-04-05
License: --

This package incorporates the functions EOQ and EOQcoo, which compute the optimal policy in an EOQ model. For studying the optimal orders and costs in an EPQ model, functions EPQ and EPQcoo can be used. The package includes the function SOC for the SOC allocation rule. For the inventory transportation system (STI), the functions STI, STIcoo and reglalineacoalitional implement the associated games to these situations and their allocation rule (line rule). The function mfoc calculates the optimal order and its associated cost to model with fixed order cost (MFOC). Shapley value can be obtained for this class of games with the function shapley\_mfoc. The basic EOQ system without holding costs and with transportation cost (MCT) can be studied with the functions mct and twolines (allocation rule). This package includes the function mwhc for models without holding costs (MWHC), the function mwhc2c when two suppliers are considered with differents costs of the product and the function mwhcct when the transportation costs are considered (MWHCCT).

Author(s)

Saavedra-Nieves, Alejandro

Maintainer: Alejandro Saavedra-Nieves <[email protected]>

References

M.G. Fiestras-Janeiro, I. García–Jurado, A. Meca, M. A. Mosquera (2011). Cooperative game theory and inventory management. European Journal of Operational Research, 210(3), 459–466.

M.G. Fiestras-Janeiro, I. García-Jurado, A. Meca, M. A. Mosquera (2012). Cost allocation in inventory transportation systems. Top, 20(2), 397–410.

M.G.~ Fiestras-Janeiro, I.~ García-Jurado, A.~Meca, M. A. ~Mosquera (2014). Centralized inventory in a farming community. Journal of Business Economics, 84(7), 983–997.

M.G. Fiestras-Janeiro, I. García-Jurado, A. Meca, M.A. Mosquera (2015). Cooperation on capacitated inventory situations with fixed holding costs. emphEuropean Journal of Operational Research, 241(3), 719–726.

A. Meca (2007). A core-allocation family for generalized holding cost games. Mathematical Methods of Operation Research, 65, 499–517.

A. Meca, I. Garc\'ia-Jurado, P. Borm (2003). Cooperation and competition in inventory games. Mathematical Methods of Operations Research, 57(3), 481–493.

A. Meca, J. Timmer, I. García-Jurado, P. Borm (1999). Inventory games. Discussion paper, 9953, Tilburg University.

A. Meca, J. Timmer, I. García-Jurado, P. Borm (2004). Inventory games. European Journal of Operational Research, 156(1), 127–139.

M.A. Mosquera, I. García-Jurado, M.G. Fiestras-Janeiro (2008). A note on coalitional manipulation and centralized inventory management. Annals of Operations Research, 158(1). 183–188.

A. Saavedra-Nieves, I. García-Jurado, M.G. Fiestras-Janeiro (2017a). Placing joint orders when holding costs are negligible and shortages are not allowed. Game Theory in Management Accounting: Implementing Incentives and Fairness (to appear).

A. Saavedra-Nieves, I. García-Jurado, M.G. Fiestras-Janeiro (2017b). On coalition formation in a non-convex multi-agent inventory problem. Submitted in Annals of Operations Research.


Inventorygames

Description

Generic function to show the associated cost game to a EOQ or EPQ model.

Usage

inventorygames(n = NA, a = NA, d = NA, h = NA, m = NA, r = NA, b = NA, 
model = c("EOQ", "EPQ"))

Arguments

n

Number of agents in the inventory model.

a

The fixed cost per order.

d

Vector. Deterministic demands per time unit to each agent.

h

Vector. Holding costs to each agent.

m

Vector. Number of orders to each agent (optional).

r

Vector. Replacement rate to each agent. In general, r>d.

b

Vector. Cost of a shortage to each agent.

model

Model to be selected. EOQ and EPQ models can be considered.

Value

The characteristic function of the associated cost game is calculated to model EOQ or EPQ.

Examples

inventorygames(n=3,a=600,d=c(500,300,400),h=c(9.6,11,10),model="EOQ")
#EOQ model
#Cooperative case
#Optimal order
#    Coalition        1        2        3 Coalitional costs
#1           0   0.0000   0.0000   0.0000             0.000
#2     '{ 1 }' 250.0000   0.0000   0.0000          2400.000
#3     '{ 2 }'   0.0000 180.9068   0.0000          1989.975
#4     '{ 3 }'   0.0000   0.0000 219.0890          2190.890
#5   '{ 1,2 }' 192.4501 115.4701   0.0000          3117.691
#6   '{ 1,3 }' 184.6372   0.0000 147.7098          3249.615
#7   '{ 2,3 }'   0.0000 121.6327 162.1770          2959.730
#8 '{ 1,2,3 }' 157.4592  94.4755 125.9673          3810.512

inventorymodelfunction

Description

General function in Inventorymodel package for obtaining the optimal policy by selecting any model and its corresponding parameters.

Usage

inventorymodelfunction(model=c("EOQ","EPQ","STI","FOC","MCT","MWHC","MWHC2","MWHCCT"),
n=NA,a=NA,av=NA,d=NA,h=NA,m=NA,r=NA,K=NA,b=NA,c1=NA,c2=NA,
cooperation=c(0,1),allocation=c(0,1))

Arguments

model

Model to be selected. EOQ, EPQ, STI, mfoc, mct, mwhc, mwhc2c or mwhcct models can be considered.

n

Number of agents in the inventory model.

a

The fixed cost per order.

av

Vector. Transportation costs to each agent.

d

Vector. Deterministic demands per time unit to each agent.

h

Vector. Holding costs to each agent.

m

Vector. Number of orders to each agent(optional).

r

Vector. Replacement rate to each agent. In general, r>d.

K

Vector. Warehouse capacity to each agent.

b

Vector. Shortage cost to each agent.

c1

Value. Cost of a product from the first supplier.

c2

Value. Cost of a product from the second supplier.

cooperation

Option to indicate cooperation. If it exists cooperation=1 else cooperation=0.

allocation

Option to indicate the allocation. If it is required allocation=1 else allocation=0.

See Also

EOQ, EOQcoo, EPQ, EPQcoo, STI, STIcoo, mct, mfoc, mwhc, mwhc2c and mwhcct.

Examples

inventorymodelfunction(model="MCT",n=3,a=400,av=c(300,500,200),d=c(2,2,5),K=c(9,8,7),
cooperation=1,allocation=1)
#MCT model
#Cooperative case
#Two-lines rule
#$`Optimal solution`
#  1 2 3 Coalition     Cost
#  0 0 0         0   0.0000
#  1 0 0         1 155.5556
#  0 1 0         2 225.0000
#  0 0 1         3 428.5714
#  1 1 0        12 225.0000
#  1 0 1        13 500.0000
#  0 1 1        23 642.8571
#  1 1 1       123 642.8571
#
#$`Allocation two-lines rule`
#[1]   0.0000 219.6429 423.2143

Line rule

Description

Line rule for an inventory transportation system when coalition N is formed.

Usage

linerule(n=NA,a=NA,av=NA,d=NA,h=NA,m=NA)

Arguments

n

Agents in the inventory situation.

a

The fixed cost per order.

av

Vector. The transportations cost per order to each agent.

d

Vector. Deterministic demands per time unit to each agent.

h

Vector. Holding cost per time unit to each agent.

m

Vector. Number of orders to each agent (optional).

Value

Allocation for each agent if N was formed.

Examples

linerule(n=3,a=200,av=c(300,300,900),d=c(90,80,20),h=c(0.06,0.06,0.1),m=NA)

#Line rule
#[1] 51.38935 46.10733 66.33250

Line rule (coalitional)

Description

Line rule for an inventory transportation system for each possible coalition.

Usage

linerulecoalitional(n = NA, a = NA, av = NA, d = NA, h = NA, m = NA)

Arguments

n

Agents in the inventory situation.

a

The fixed cost per order.

av

Vector. The transportations cost per order to each agent.

d

Vector. Deterministic demands per time unit to each agent.

h

Vector. Holding cost per time unit to each agent.

m

Vector. Number of orders to each agent (optional).

Value

Matrix with allocations proposed by Line rule to agents (columns) in each possible coalition S (row).

Examples

linerulecoalitional(n=3,a=200,av=c(300,300,900),d=c(90,80,20),
h=c(0.06,0.06,0.1),m=NA)

#    Coalition        1        2       3 Coalitional cost
#1           0  0.00000  0.00000  0.0000          0.00000
#2     '{ 1 }' 73.48469  0.00000  0.0000         73.48469
#3     '{ 2 }'  0.00000 69.28203  0.0000         69.28203
#4     '{ 3 }'  0.00000  0.00000 66.3325         66.33250
#5   '{ 1,2 }' 52.59885 48.39619  0.0000        100.99505
#6   '{ 1,3 }' 61.26061  0.00000 66.3325        127.59310
#7   '{ 2,3 }'  0.00000 55.97858 66.3325        122.31108
#8 '{ 1,2,3 }' 51.38935 46.10733 66.3325        163.82918

fauxiliar

Description

Intermediate auxiliar function to calculate the mean of the marginal contributions for a set of permutations.

Usage

marginal_contribution_mean(permute, costs)

Arguments

permute

Matrix with n columns. By rows, it contains a order.

costs

Vector with the associated costs to each posible coalition in a set of agents N.

Value

A vector with n elements with component i equal to the mean of the marginal contribution indicated by each order in permute for agent i.


MCT

Description

This function obtains the associated costs in a basic EOQ system without holding costs and with transportation cost.

Usage

mct(n = NA, a = NA, av = NA, d = NA, K = NA, cooperation = c(0, 1))

Arguments

n

Agents in the inventory situation.

a

The fixed cost per order.

av

Vector. The transportations cost per order to each agent.

d

Vector. Deterministic demands per time unit to each agent.

K

Vector. Warehouse's capacity to each agent.

cooperation

Option to indicate cooperation. If it exists cooperation=1 else cooperation=0.

Value

If cooperation=0, a vector with the individual cost to each agent in a MCT. If cooperation=1 and n is lesser than 0, a matrix which contains the associated costs for each possible group. Otherwise, this matrix only contains the individual costs and the associated values for N.

Examples

mct(n=3,a=400,av=c(300,500,200),d=c(2,2,5),K=c(9,8,7),cooperation=0)

#MCT model
#Individual cost
#[1] 155.5556 225.0000 428.5714

MFOC

Description

This function obtains the associated costs in a fixed order cost model.

Usage

mfoc(n = NA, a = NA, d = NA, K = NA, cooperation = c(0, 1))

Arguments

n

Agents in the inventory situation.

a

The fixed cost per order.

d

Vector. Deterministic demands per time unit to each agent.

K

Vector. Warehouse's capacity to each agent.

cooperation

Option to indicate cooperation. If it exists cooperation=1 else cooperation=0.

Value

If cooperation=0, a vector with the individual cost to each agent in a MFOC. If cooperation=1 and n is lesser than 0, a matrix which contains the associated costs for each possible group. Otherwise, this matrix only contains the individual costs and the associated values for N.

Examples

mfoc(n=3,a=200,d=c(1.2,1.4,1.2),K=c(6,10,8),cooperation=0)

#MFOC model
#[1] 40 28 30

MWHC

Description

This function obtains the associated costs in a model without holding costs. Demands and capacities must be introduced in the order indicated by the ratios d/K. In other case, agents change their position.

Usage

mwhc(n = NA, a = NA, b = NA, d = NA, K = NA, cooperation = c(0, 1), 
allocation = c(0, 1))

Arguments

n

Agents in the inventory situation.

a

The fixed cost per order.

b

Vector. Shortage cost per unit to each agent.

d

Vector. Deterministic demands per time unit to each agent.

K

Vector. Warehouse's capacity to each agent.

cooperation

Option to indicate cooperation. If it exists cooperation=1 else cooperation=0.

allocation

Option to indicate the allocation. If it is required allocation=1 else allocation=0.

Value

A list with the following components:

  • "Optimal policies" If n is lesser than 0, a matrix with all possible coalitions in the first column. The second column contains the optimal order to each coalition. Last column indicates the global cost of this optimal order. Otherwise, this matriz contains the individual costs and the associated values for N.

  • "R-rule" A matrix, for each coalition (row), contains the coalition i(S) and allocations proposed by R-rule.

Examples

mwhc(n=4,a=180,b=c(15,15,10,12),d=c(0.45,0.95,1.05,1.2),K=c(5,7.5,8,9),
cooperation=1,allocation=1)

#MWHC model
#Cooperative case
#$`Optimal policies`
#      Coalitions Optimal orders    Costs
#1              0     0.00000000  0.00000
#2        '{ 1 }'     0.07520921 14.74965
#3        '{ 2 }'     0.10684954 20.86510
#4        '{ 3 }'     0.10406757 20.89599
#5        '{ 4 }'     0.11094004 21.79985
#6      '{ 1,2 }'     0.10684954 20.86510
#          ..   
#
#$`R-rule`
#  Coalition_SxT        1         2         3        4
#              0  0.00000  0.000000  0.000000  0.00000
#              1 14.74965  0.000000  0.000000  0.00000
#              2  0.00000 20.865100  0.000000  0.00000
#              3  0.00000  0.000000 20.895986  0.00000
#              4  0.00000  0.000000  0.000000 21.79985
#              2  0.00000 20.865100  0.000000  0.00000
#              3  0.00000  0.000000 20.895986  0.00000
#             ..

MWHC2C

Description

This function obtains the associated costs in a model without holding costs and with two differents cost of product. Demands and capacities must be introduced in the order indicated by the ratios d/K. In other case, agents change their position.

Usage

mwhc2c(n=NA,a=NA,b=NA,d=NA,K=NA,c1=NA,c2=NA,cooperation=c(0,1),allocation=c(0,1))

Arguments

n

Agents in the inventory situation.

a

The fixed cost per order.

b

Vector. Shortage cost per unit to each agent.

d

Vector. Deterministic demands per time unit to each agent.

K

Vector. Warehouse's capacity to each agent.

c1

Value. Cost per unit of product from the first vendor.

c2

Value. Cost per unit of product from the second vendor.

cooperation

Option to indicate cooperation. If it exists cooperation=1 else cooperation=0.

allocation

Option to indicate the allocation. If it is required allocation=1 else allocation=0.

Value

A list with the following components:

  • "Optimal policies" If n is lesser than 0, a matrix with all possible coalitions in the first column. The second column contains the optimal order to each coalition. Last column indicates the global cost of this optimal order. Otherwise, this matriz contains the individual costs and the associated values for N.

  • "GR-rule" A matrix, for each coalition (row), contains the coalition i(S) and allocations proposed by GR-rule.

Examples

mwhc2c(n=3,a=1,b=c(10,10,10),d=c(30,45,46),K=c(30,45,46),c1=3.5,c2=3,cooperation=1,allocation=1)
#MWHC model
#$`Optimal policies`
#   Coalitions Optimal orders    Costs
#1           0      0.0000000   0.0000
#2     '{ 1 }'      0.9505864 105.5947
#3     '{ 2 }'      0.9515422 157.9165
#4     '{ 3 }'      0.9515838 161.4046
#5   '{ 1,2 }'      0.9523090 262.5595
#6   '{ 1,3 }'      0.9523241 266.0476
#7   '{ 2,3 }'      0.9525115 318.3690
#8 '{ 1,2,3 }'      0.9527470 423.0118
#
#$`GR-rule`
#  Coalition_SxT        1        2        3
#              0   0.0000   0.0000   0.0000
#              1 105.5947   0.0000   0.0000
#              2   0.0000 157.9165   0.0000
#              3   0.0000   0.0000 161.4046
#             12 105.0238 157.5357   0.0000
#             13 105.0188   0.0000 161.0288
#             23   0.0000 157.4352 160.9338
#            123 104.8790 157.3184 160.8144

MWHCCT

Description

This function obtains the associated costs in a basic EOQ system without holding costs and with a general transportation cost.

Usage

mwhcct(n = NA, a = NA, av = NA, d = NA, K = NA, cooperation = c(0, 1),allocation = c(0,1))

Arguments

n

Agents in the inventory situation.

a

The fixed cost per order.

av

Vector. The transportations cost per order to each possible group of agents.

d

Vector. Deterministic demands per time unit to each agent.

K

Vector. Warehouse's capacity to each agent.

cooperation

Option to indicate cooperation. If it exists cooperation=1 else cooperation=0.

allocation

Option to indicate the allocation. If it is required allocation=1 else allocation=0.

Value

If n is lesser than 0, a matrix with all possible coalitions in the first column. The next n columns contain the associated cost to each agent in the coalition. Last column indicates the global cost of the optimal order. Otherwise, this matriz contains the individual costs and the associated values for N.

Examples

mwhcct(n=3,a=10,av=c(0,10,10,10,20,20,20,30),d=c(1,0.95,0.9),K=c(1,1,1),
cooperation=1,allocation = 1)
# MWHC with Transportation Costs model
#Cooperative case
#[1] "Shapley Value"
#$`Optimal solution`
#  1 2 3   Coalition Cost
#1 0 0 0           0  0.0
#2 1 0 0     '{ 1 }' 20.0
#3 0 1 0     '{ 2 }' 19.0
#4 0 0 1     '{ 3 }' 18.0
#5 1 1 0   '{ 1,2 }' 30.0
#6 1 0 1   '{ 1,3 }' 30.0
#7 0 1 1   '{ 2,3 }' 28.5
#8 1 1 1 '{ 1,2,3 }' 40.0
#
#$`Allocation R rule`
#      1     2  3
#  13.75 13.25 13

SMFOC

Description

Function to calculate the Shapley value for the associated game to a fixed order cost model.

Usage

shapley_mfoc(n = NA, a = NA, d = NA, K = NA)

Arguments

n

Agents in the inventory situation.

a

The fixed cost per order.

d

Vector. Deterministic demands per time unit to each agent.

K

Vector. Warehouse's capacity to each agent.

Value

Shapley value for the associated game to the fixed order cost model.

Examples

shapley_mfoc(n=5,a=200,d=c(1.2,1.4,1.2,1.3,0.4),K=c(6,10,8,8,4))

#Shapley-Value
#MFOC model
#[1]  4.000000  6.000000  6.666667  7.916667 15.416667

SOC

Description

Generic function for showing the allocations proposed by SOC rule under an EOQ or EPQ model.

Usage

SOC(n = NA, a = NA, d = NA, h = NA, m = NA, r = NA, b = NA, 
model = c("EOQ", "EPQ"))

Arguments

n

Number of agents in the inventory model.

a

The fixed cost per order.

d

Vector. Deterministic demands per time unit to each agent.

h

Vector. Holding costs to each agent.

m

Vector. Number of orders to each agent(optional).

r

Vector. Replacement rate to each agent. In general, r>d.

b

Vector. Cost of a shortage to each agent.

model

Model to select. EOQ and EPQ models can be considered.

Value

Matrix with number of rows equal to the number of coalitions and n columns. For each coalition or row, the output shows the cost that SOC rule allocates to each player or column.

Examples

SOC(n=3,a=600,d=c(500,300,400),h=c(9.6,11,10),m=NA,r=NA,b=NA,model="EOQ")

#EOQ model
#$`Share the ordering costs rule (individually)`
#[1] 2400.000 1989.975 2190.890

SOC(n=3,a=600,d=c(500,300,400),h=c(9.6,11,10),m=NA,r=NA,b=NA,model="EOQ")

#EOQ model
#$`Share the ordering costs rule (individually)`
#         1        2        3
#     0.000    0.000    0.000
#  2400.000    0.000    0.000
#     0.000 1989.975    0.000
#     0.000    0.000 2190.890
#  1847.521 1270.171    0.000
#  1772.517    0.000 1477.098
#     0.000 1337.960 1621.770
#  1511.608 1039.230 1259.673

STI

Description

This function obtains the optimal orders and the associated cost when agents are cooperating in the inventory transportation system.

Usage

STI(n = NA, a = NA, av = NA, d = NA, h = NA, m = NA)

Arguments

n

Agents in the inventory situation.

a

The fixed cost per order.

av

Vector. The transportations cost per order to each agent.

d

Vector. Deterministic demands per time unit to each agent.

h

Vector. Holding cost per time unit to each agent.

m

Vector. Number of orders to each agent (optional).

Value

This function calculates two vectors. The first one shows the optimal order for each agent. The second vector indicates the associated cost to these orders.

Examples

STI(n=3,a=200,av=c(300,300,900),d=c(90,80,20),h=c(0.06,0.06,0.1),m=NA)
#STI model
#$"Optimal order"
#[1] 1224.745 1154.701  663.325
#
#$"Order cost"
#[1] 73.48469 69.28203 66.33250

STIcoo

Description

This function obtains the optimal orders and the associated cost when agents are cooperating in the inventory transportation system when agents are cooperating.

Usage

STIcoo(n = NA, a = NA, av = NA, d = NA, h = NA, m = NA)

Arguments

n

Agents in the inventory situation.

a

The fixed cost per order.

av

Vector. The transportations cost per order to each agent.

d

Vector. Deterministic demands per time unit to each agent.

h

Vector. Holding cost per time unit to each agent.

m

Vector. Number of orders to each agent (optional).

Value

A list with the following components:

  • Optimal order If n is lesser than 0, a matrix with all possible coalitions in the first column. The next n columns contain the associated cost to each agent in the coalition. Last column indicates the global cost of the optimal order. Otherwise, this matriz contains the individual costs and the associated values for N.

Examples

STIcoo(n=3,a=200,av=c(300,300,900),d=c(90,80,20),h=c(0.06,0.06,0.1),m=NA)

#$`Optimal order`
#          1        2        3   Coalition Order cost
#1    0.0000    0.000   0.0000           0    0.00000
#2 1224.7449    0.000   0.0000     '{ 1 }'   73.48469
#3    0.0000 1154.701   0.0000     '{ 2 }'   69.28203
#4    0.0000    0.000 663.3250     '{ 3 }'   66.33250
#5  891.1328  792.118   0.0000   '{ 1,2 }'  100.99505
#6 1551.8080    0.000 344.8462   '{ 1,3 }'  127.59310
#7    0.0000 1438.954 359.7385   '{ 2,3 }'  122.31108
#8 1208.5759 1074.290 268.5724 '{ 1,2,3 }'  163.82918

Two-lines rule

Description

Two-lines rule for a basic EOQ system without holding costs and with transportation cost.

Usage

twolines(n = NA, a = NA, av = NA, d = NA, K = NA)

Arguments

n

Agents in the inventory situation.

a

The fixed cost per order.

av

Vector. The transportations cost per order to each agent.

d

Vector. Deterministic demands per time unit to each agent.

K

Vector. Capacities of agents' warehouse to each agent.

Value

The output is a vector who contains the allocation to each player.

Examples

twolines(n=3,a=400,av=c(300,500,200),d=c(2,2,5),K=c(9,8,7))
#MCT model
#Cooperative case
#Two-lines rule
#[1]   0.0000 219.6429 423.2143