Step-1 Install sales module.

Step-2 After that sales module.

In below example, I have customized sales module. You can directly use the below sales module in your addons and run in Odoo server.

from openerp.osv import fields, osv
from openerp.tools.translate import _
from openerp import SUPERUSER_ID
from openerp import api


class sup_brand(osv.osv):
	_name = "supplier.brand"
	_rec_name = "supplier_brand"
	_columns = {
				'supplier_brand':fields.char('Supplier Brand'),
	}
sup_brand()

class sup_refrence(osv.osv):
	_name = "supplier.refrence"
	_rec_name = "item_list"
	_columns = {
				'item_list' : fields.char('Supplier reference'),
	}
sup_refrence()

class colour_code(osv.osv):
	_name = "colour.code"
	_rec_name = "color_code"
	_columns = {
				'color_code':fields.char('Color Code'),
	}
colour_code()

class colour_name(osv.osv):
	_name = "colour.name"
	_rec_name = "color_name"
	_columns = {
				'color_name':fields.char('Color Name'),
	}
colour_name()

class product_template(osv.osv):
    _name = "product.template"
    _inherit = "product.template"
    _columns = {
                'l_price': fields.float('Lower Price'),
				'supp_ref' : fields.char('I Type'),
                'project_price' : fields.float('Project Price'),
                'distributor_pirce' : fields.float('Distributor price'),
                'squ_meter':fields.float('Square Meter', digits=(8,3)),
                'qty_warehous_onhand': fields.float('Qty Sqm in Warehouse', compute='_compute_qty_warehous_onhand', require = True),
                'qty_available_onhand': fields.float('Qty Sqm Available', compute='_compute_qty_available_onhand', require = True),
                'qty_avb':fields.related('qty_available', relation='product.product', string='Quantity on Hand'),
                'qty_avl':fields.related('virtual_available', relation='product.product', string='Quantity on Hand'),
                'opening_stock':fields.float('Opening Stock'),
                'size':fields.char('Size'),
                'unit_measure':fields.char('Unit Of Measure'),
                'item_list' : fields.many2one('supplier.refrence','Supplier reference'),
                'supplier_brand':fields.many2one('supplier.brand','Supplier Brand'),
				'color_code':fields.many2one('colour.code','Color Code'),
                'color_name':fields.many2one('colour.name','Color Name'),
                }
                
              
    def button_dummy(self, cr, uid, ids, context=None):
        return True
                
                
    @api.depends('qty_avb','squ_meter')
    def _compute_qty_warehous_onhand(self):
        for record in self:
            print "sssssssss", record.qty_avb
            print "sssssssss", record.squ_meter
            print "sssssssss", record._compute_qty_warehous_onhand
            record.qty_warehous_onhand = record.qty_avb * record.squ_meter
    
                    
    @api.depends('qty_avl', 'squ_meter')
    def _compute_qty_available_onhand(self):
        for record in self:
            record.qty_available_onhand = record.qty_avl * record.squ_meter
#            print "plsssssssssssssssss", record.qty_warehous_onhand       

product_template()


class product_product(osv.osv):
    _name = "product.product"
    _inherit = "product.product"
    
    def name_get(self, cr, user, ids, context=None):
        if context is None:
            context = {}
        if isinstance(ids, (int, long)):
            ids = [ids]
        if not len(ids):
            return []

        def _name_get(d):
            name = d.get('name','')
            code = context.get('display_default_code', True) and d.get('default_code',False) or False
            item_list = d.get('item_list', '')
            print item_list , 'the following is the supplier refrence code'
#            if code:
#                name = '[%s] %s' % (code,name)
#            return (d['id'], name)
            if item_list:
                name = '[%s] - [%s] %s' % (code,item_list,name)
            return (d['id'], name)
        partner_id = context.get('partner_id', False)
        if partner_id:
            partner_ids = [partner_id, self.pool['res.partner'].browse(cr, user, partner_id, context=context).commercial_partner_id.id]
        else:
            partner_ids = []

        # all user don't have access to seller and partner
        # check access and use superuser
        self.check_access_rights(cr, user, "read")
        self.check_access_rule(cr, user, ids, "read", context=context)

        result = []
        for product in self.browse(cr, SUPERUSER_ID, ids, context=context):
            variant = ", ".join([v.name for v in product.attribute_value_ids])
            name = variant and "%s (%s)" % (product.name, variant) or product.name
            sellers = []
            if partner_ids:
                sellers = filter(lambda x: x.name.id in partner_ids, product.seller_ids)
            if sellers:
                for s in sellers:
                    seller_variant = s.product_name and (
                        variant and "%s (%s)" % (s.product_name, variant) or s.product_name
                        ) or False

                    mydict = {
                              'id': product.id,
                              'name': seller_variant or name,
                              'default_code': s.product_code or product.default_code,
                              'item_list' : product.item_list,
                              }
                    result.append(_name_get(mydict))
            else:
                mydict = {
                          'id': product.id,
                          'name': name,
                          'default_code': product.default_code,
                          'item_list' : product.item_list,
                          }
                result.append(_name_get(mydict))
        return result
        
product_product()