AFS allocation run

Hi,

I'm having an issue in allocation of sales orders (SAP AFS). I've a sales order with 1 material with qty 5000. I allocated 1000 units and created delivery. The MRP satatus in J_3ABDBS table shows D. Now I'm not able to allocate rest of the qty in sales order. Can someone help me out in this situation? What all places I need to check the settings?

Thanks,

KC