this is the data value and the objective function must be $68$: $\%$This first case is a very simple test on $2$ days and $2$ wind turbines

$\%$You can solve it by hand to be sure of your result and modify the data for testing purposes

n$\_$employee $=1$;

n$\_$turbine $=2$;

n$\_$tasks $=3$;

n$\_$week $=1$;

n$\_$day $=2$;

n$\_$period $=$ n$\_$day$*3$; $\%3$ periods per day

$\%$productivity of an wind turbine at each period

productivity $=$ array$2$d$(1..$n$\_$turbine,$1..$n$\_$period,$[10,8,10,8,9,9,$

$10,5,6,7,9,9])$;

$\%$duration and location of each task

on$\_$turbine $=$ array$1$d$(1..$n$\_$tasks,$[1,1,2])$;

length $=$ array$1$d$(1..$n$\_$tasks,$[1,1,2])$;

here is the minizinc code: include "globals.mzn$"$;

$\%$ Parameters

int: n$\_$tasks; $\%$ Number of tasks

int: n$\_$turbine; $\%$ Number of turbines

int: n$\_$employee; $\%$ Number of employees

int: n$\_$period; $\%$ Number of time periods

int: n$\_$week; $\%$ Number of weeks

int: n$\_$day; $\%$ Number of days

$\%$ Input Data

array$[1..$n$\_$turbine, $1..$n$\_$period$]$ of int: productivity; $\%$ Productivity of each turbine per period

array$[1..$n$\_$tasks$]$ of int: on$\_$turbine; $\%$ Turbine assigned to each task

$\%$ Decision Variables

array$[1..$n$\_$tasks$]$ of var $1..$n$\_$period: start$\_$time; $\%$ Start time of each task

array$[1..$n$\_$tasks$]$ of var $1..$n$\_$period: end$\_$time; $\%$ End time of each task

array$[1..$n$\_$tasks$]$ of var $1..$n$\_$period: length; $\%$ Duration of each task

array$[1..$n$\_$turbine$]$ of var int: loss$\_$turbine; $\%$ Productivity loss for each turbine

$\%$ Derived Variables

array$[1..$n$\_$turbine$]$ of var int: total$\_$productivity $=[$

sum$($p in $1..$n$\_$period$)($productivity$[$t$,$ p$])|$ t in $1..$n$\_$turbine

$]$;

$\%$ Constraints

$\%1.$ No two tasks on the same turbine can overlap

constraint forall$($t in $1..$n$\_$turbine$)($

cumulative$($

$[$start$\_$time$[$i$]|$ i in $1..$n$\_$tasks where on$\_$turbine$[$i$]=$ t$],$

$[$length$[$i$]|$ i in $1..$n$\_$tasks where on$\_$turbine$[$i$]=$ t$],$

$[1|$ i in $1..$n$\_$tasks where on$\_$turbine$[$i$]=$ t$],$

$1$

$)$

$)$;

$\%2.$ Duration calculation

constraint forall$($i in $1..$n$\_$tasks$)($

length$[$i$]=$ end$\_$time$[$i$]-$ start$\_$time$[$i$]+1$

$)$;

$\%3.$ Each employee handles only one task at a time

constraint cumulative$($start$\_$time, length, $[1|\_$ in $1..$n$\_$tasks$],$ n$\_$employee$)$;

$\%4.$ Calculation of productivity losses for each turbine

constraint forall$($t in $1..$n$\_$turbine$)($

loss$\_$turbine$[$t$]=$ sum$($p in $1..$n$\_$period$)($

sum$($i in $1..$n$\_$tasks where on$\_$turbine$[$i$]=$ t$)($

bool$2$int$($start$\_$time$[$i$]<=$ p $/\backslash$ p $<=$ end$\_$time$[$i$])*$ productivity$[$t$,$ p$]$

$)$

$)$

$)$;

$\%$ Objective Function

var int: actual$\_$productivity $=$ sum$($t in $1..$n$\_$turbine$)($

total$\_$productivity$[$t$]-$ loss$\_$turbine$[$t$]$

$)$;

solve maximize actual$\_$productivity;

please correct the code for me in order to get $68$ as objective function value.