Need help to reduce execution time for a procedure

Question

the following procedure takes to long to execute and the server times out. each individual select works perfectly. It does not have to do with the SORT_AREA_SIZE/PGA_AGGREGATE_TARGET not being large enough. Possible rewriting it in funcions might help i don't know.
Thanks in advance
PROCEDURE GET_RM_WORKABILITY_BY_PLANT
            (p_in_plantcode IN VARCHAR2,
            p_in_statusnum IN NUMBER,
            p_out_cursor     IN OUT tcursor) AS
    BEGIN
      OPEN p_out_cursor FOR
          select comp.segment1,
                  comp.description,
                  comp.organization_id,
                  nvl(sum(jot.qty), 0) job_qty,
                  nvl(moq.qty, 0) onhand_qty
          from   (select jdl.bill_sequence_id bsid,
                            sum(jdl.job_qty) qty
                  from        job_detail_lines jdl
                  where   jdl.job_stat = p_in_statusnum
                    and   jdl.prod_plant_id = p_in_plantcode
                  group by jdl.bill_sequence_id) jot,
                  (select m.inventory_item_id,
                               sum(m.transaction_quantity) qty
                    from   mtl_onhand_quantities m
                    where  exists
                              (select 'x'
                             from   plant_codes p1,
                                      plant_codes p
                              where  p.plant_code = p_in_plantcode
                                and  p1.fac_id = p.fac_id
                                and  m.organization_id = p1.organization_id)
                    group by m.inventory_item_id) moq,
                    (select msi.segment1,
                            msi.description,
                            msi.organization_id,
                            msi.inventory_item_id,
                            bom.bill_sequence_id
                    from   bom.bom_bill_of_materials bom,
                            bom.bom_inventory_components bic,
                            mtl_system_items msi,
                            plant_codes pc
                    where  pc.plant_code = p_in_plantcode
                      and  msi.organization_id = pc.organization_id
                      and  msi.item_type||'' IN ('PSSRM', 'PSRM')
                      and  bic.component_item_id = msi.inventory_item_id
                      and  ((bic.disable_date IS NULL AND SYSDATE>= bic.effectivity_date)
                              or (SYSDATE <= bic.disable_date AND SYSDATE >= bic.effectivity_date))
                      and  bom.bill_sequence_id = bic.bill_sequence_id
                      and  bom.organization_id = 102) comp
          where  moq.inventory_item_id(+) = comp.inventory_item_id
            and  jot.bsid(+) = comp.bill_sequence_id
          group by comp.segment1,
                       comp.description,
                     comp.organization_id,
                     moq.qty;
END;

Answer 1

Ok, so how does it perform if you use the bom info as an in-line query outer join to job detail lines?
SELECT v.plant_code,
       v.segment1,
       v.description,
       v.organization_id,
       v.inventory_item_id,
       SUM (jdl.job_qty) job_qty
  FROM (
SELECT pc.plant_code,
       msi.segment1,
       msi.description,
       msi.organization_id,
       msi.inventory_item_id,
       bom.bill_sequence_id
  FROM bom.bom_bill_of_materials bom,
       bom.bom_inventory_components bic,
       mtl_system_items msi,
       plant_codes pc
WHERE pc.plant_code = p_in_plantcode
   AND msi.organization_id = pc.organization_id
   AND msi.item_type || '' IN ('PSSRM', 'PSRM')
   AND bic.component_item_id = msi.inventory_item_id
   AND bic.effectivity_date <= SYSDATE
   AND (   bic.disable_date IS NULL
        OR bic.disable_date >= SYSDATE)
   AND bom.bill_sequence_id = bic.bill_sequence_id
   AND bom.organization_id = 102
       )  v,
       job_detail_lines  jdl
WHERE jdl.prod_plant_id(+) = v.plant_code
   AND jdl.bsid(+) = v.bill_sequence_id
   AND jdl.job_stat(+) = p_in_statusnum
GROUP BY
       v.plant_code,
       v.segment1,
       v.description,
       v.organization_id,
       v.inventory_item_id;