exp6.sce

//Simulation of Inventory Problem 
    // There are 3 day lag between order and delivery/arrival.
    // The merchandise is ordered at the end of the day(i) and received at the start of fourth day(i+3).
    // For each unit of inventory the carrying cost of each night is Rs.0.75.
    // Each unit out of stock when ordered results into the loss of goodwill worth Rs.2.0 per unit plus loss of Rs.16.00 net income,
    // that would have resulted in its sale. Or a total loss of Rs. 18.00 per unit forever.
    // The demand in a day can be for any number of units between 0 and 99, each equiprobable.
    // There is never more than one replenishment order outstanding.
    // Initially we have 115 units on hand and no reorder outstanding.

    t=(floor(rand(1:90)*100)+1) //random number generator

    x=[125,125,150,175,175] //reorder point
    y=[150,250,250,250,300] //reorder quantity
    
    for policy = 1:5
        curr=115 //no of tyres in stock
        p=0 //profit
        l=0 //loss
        d=3 //reorder day left
    
        for i = 1:90
            limit = x(policy)
            reorder = y(policy)
            cust = t(i) //no. of cutomers on ith day
            if(i>d) then //order arrived
                curr = curr+reorder
                d=90
            end
            if(cust>curr) then //loss
                p=p+(curr*16)
                l=l+(cust-curr)*18
                curr=0
            else
                p=cust*16 //no. loss
                curr=curr-cust
                l=l+(curr*0.75)
            end
            if((curr<=limit)&(d==90)) then //need to reorder
                d=i+3
            end
        end
        mprintf('Policy: %i\n',policy)
        mprintf('Profit: %f\n',p)
        mprintf("Loss: %f\n",l)
        mprintf("Remaining: %f\n",curr)
    end