Memory usage when repeatedly solving a problem

Hi Susanne,

thanks for your prompt response, the code below worked for me in the past (as mentionend, based on our discussions about 15 years ago :) ). I am using Win 11 with Mosel 6.0.1:

model "ND Sandbox"
version 1.0.0
uses  "mmxprs", "mmsheet", "mmsystem", "math"
!uses "mminsight" ! Mandatory for Xpress insight
 
!this file contains definition of data elements, loading of data from spreadsheet, and internal processing of arrays for later use in models
!nomenclature used: CTR: Controls, EXT: read from spreadsheet, INT: processed internally, RES: results shown to user
 
!*********** Section DEFINITION ***********
 
parameters
	CSTR= 'Sandbox Template.xlsx'													! Name of Excel file (data template)
	!CSTRout = 'E2E Risk Guru Results.xlsx' 
	CTR_MAX_ROW=2400
	CTR_ROAD_FACT=1.18
end-parameters
 
[email protected] input
public declarations 																! Insert declarations of entities that are used by the UI here
	DC: set of string
	!Sheet DC
	EXT_DC_CITY: array(DC) of string	
	EXT_DC_COUNTRY: array(DC) of string	
	EXT_DC_LAT:  array(DC) of real													! DC latitude
	EXT_DC_LON:  array(DC) of real 													! DC longitude
	EXT_DC_STATUS: array(DC) of integer	
	
	PLANT: set of string
	!Sheet Sites
	EXT_PLANT_CITY: array(PLANT) of string	
	EXT_PLANT_COUNTRY: array(PLANT) of string	
	EXT_PLANT_LAT:  array(PLANT) of real											! DC latitude
	EXT_PLANT_LON:  array(PLANT) of real 											! DC longitude
	
	CUSTOMER: set of string															! Set of customers
	! Sheet Customer
	
	EXT_CUSTOMER_CITY: array(CUSTOMER) of string	
	EXT_CUSTOMER_COUNTRY: array(CUSTOMER) of string	
	EXT_CUSTOMER_LAT:  array(CUSTOMER) of real										! Customer latitude
	EXT_CUSTOMER_LON:  array(CUSTOMER) of real 										! Customer longitude
	EXT_CUSTOMER_CHANNEL:  array(CUSTOMER) of string 								! Customer longitude
	EXT_CUSTOMER_LT:  array(CUSTOMER) of real 										! Customer longitude
 
	PRODUCT: set of string
	! Sheet demand
	EXT_DEMAND_QUANTITY: array(CUSTOMER, PRODUCT) of real
	
end-declarations
 
declarations
	ORIG_SITES: set of string
	DEST_SITES: set of string
	INT_DISTANCE: dynamic array(ORIG_SITES, DEST_SITES) of real
	INT_TRANS_OUT_COST: real
	INT_TRANS_INB_COST: real
	INT_WHS_FIX_COST: real
	INT_PLANT_SHARE: array(PRODUCT, PLANT) of real
	INT_BIGM: array(PRODUCT) of real
	INT_MAX_DISTANCE_CUST: array(CUSTOMER) of real
	!emissions
	INT_EM_OUT: real
	INT_EM_INB: real
	INT_CERTIFICATE_COST: real
	INT_EM_WHS: real
	!Controls
	INT_WHS_STRUCTURE: string
	INT_SCEN: integer
	INT_ITER: integer
	Obj: linctr
	INT_DEMAND_MULTIPLIER: real
end-declarations
 
!*********** Section LOAD DATA AND INTERNAL PROCESSING ***********
 
procedure loaddata
	![...]
	!this intialized data
end-initializations 
 
end-procedure
 
loaddata
 
![...] data preprocessing
 
procedure ND
	
declarations
	z: array(PLANT, DC, PRODUCT) of mpvar
	x: array(DC, CUSTOMER, PRODUCT) of mpvar
	y: array(DC) of mpvar
	penalty_dist: array(CUSTOMER) of mpvar
	CO2: mpvar
end-declarations
 
forall(i in DC) y(i) is_binary
 
obj:=sum(i in DC, j in CUSTOMER, k in PRODUCT) x(i,j,k)*INT_DISTANCE(i,j)*INT_TRANS_OUT_COST + sum(i in DC) y(i)*INT_WHS_FIX_COST + sum(i in PLANT, j in DC, k in PRODUCT) z(i,j,k)*INT_DISTANCE(i,j)*INT_TRANS_INB_COST + sum(j in CUSTOMER)penalty_dist(j)*9999999 + CO2/1000*INT_CERTIFICATE_COST
 
C0:=CO2=sum(i in DC, j in CUSTOMER, k in PRODUCT) x(i,j,k)*INT_DISTANCE(i,j)*INT_EM_OUT + sum(i in PLANT, j in DC, k in PRODUCT) z(i,j,k)*INT_DISTANCE(i,j)*INT_EM_INB
 
forall(i in DC, k in PRODUCT)
	C1(i,k):=sum(m in PLANT)z(m,i,k) = sum(j in CUSTOMER)x(i,j,k)
 
forall(i in DC, k in PRODUCT)
	C2(i,k):=sum(j in CUSTOMER)x(i,j,k) <= y(i)*INT_BIGM(k)
	
forall(j in CUSTOMER, k in PRODUCT)
	C3(j,k):=sum(i in DC)x(i,j,k) >= EXT_DEMAND_QUANTITY(j,k)*INT_DEMAND_MULTIPLIER
	
forall(i in DC) do
if EXT_DC_STATUS(i)=1 then
	y(i)=1
end-if
if EXT_DC_STATUS(i)=0 then
	y(i)=0
end-if
end-do
 
forall(i in DC, j in CUSTOMER, k in PRODUCT)
	C4(i,j,k):=x(i,j,k)*INT_DISTANCE(i,j) <= x(i,j,k)*INT_MAX_DISTANCE_CUST(j) + penalty_dist(j)
	
minimize(obj)
 
![...] write output to console
 
!Release Constraints
C0:=0
Obj:=0
forall(i in DC, k in PRODUCT)
	C1(i,k):=0
forall(i in DC, k in PRODUCT)
	C2(i,k):=0	
forall(j in CUSTOMER, k in PRODUCT)
	C3(j,k):=0
forall(i in DC, j in CUSTOMER, k in PRODUCT)
	C4(i,j,k):=0
 
!unloadprob
end-procedure
 
!****************************************************************************************
 
!ENUMERATION
 
!HERE I Call ND in a loop that enumerates all combination of y(i): 12 DCs --> 2^12 combinations plus further loops for sensitivity to data such as fixed cost
 
 
end-model

I shortened [...] this a little bit. the procedure ND should be called repeatedly for enumerating results and sensitivity analysis.

Thanks

David