int: nMachines;
int: nOuvriers;

set of int: MACHINES = 1..nMachines;
set of int: OUVRIERS = 1..nOuvriers;


array[OUVRIERS,MACHINES] of int : productivite;

var int: total;

array[OUVRIERS,MACHINES] of var bool: x;

% Constraints

constraint forall(o in OUVRIERS)(sum(m in MACHINES)(x[o,m]) == 1);
constraint forall(m in MACHINES)(sum(o in OUVRIERS)(x[o,m]) == 1);

% First Situation
%constraint total = sum(o in OUVRIERS, m in MACHINES)(x[o,m] * productivite[o,m]);

% Second Situation
constraint forall(o in OUVRIERS)(total <= sum(m in MACHINES)(productivite[o,m] * x[o,m]));

solve maximize total;