I have my own custom module, named master.py

from openerp.osv import fields, osv
from openerp.tools.translate import _
from openerp import tools
import datetime
import itertools 

class mmr_brand(osv.osv):
	_name = "mmr.brand"
	_description = "Brand Module for PT.MMR, for easier input and prevent duplication."
	
	_columns = {
		'name': fields.char("Brand", required=True),
		'notes' : fields.char("Notes"),
	}	
	
mmr_brand()	

class mmr_unit(osv.osv):
	_name = "mmr.unit"
	_description = "Unit Module for PT.MMR, for easier input and prevent duplication."
	
	_columns = {
		'name': fields.char("Unit", required=True),
		'notes' : fields.char("Notes"),
	}	
	
mmr_unit()	


class mmr_product(osv.osv):
	
	_name = "mmr.product"
	_description = "Product Module for PT.MMR, refer to Product doc."
		
	_columns = {
		'brand': fields.many2one("mmr.brand", "Brand", required=True),
		'name': fields.char("Name", required=True),
		'unit': fields.many2one("mmr.unit", "Unit", required=True),
		'minimumSellPrice': fields.float("Minimum sell price"),
	}	
	
mmr_product()

With view named master,

<openerp>
	<data>
		<record id="mmr_product_list" model="ir.ui.view">
			<field name="name">mmr.product.list</field>
			<field name="model">mmr.product</field>
			<field name="arch" type="xml">
				<tree string="Product" version="7.0">
					<field name="brand" />
					<field name="name" />
					<field name="unit" />
					<field name="minimumSellPrice" />
				</tree>
			</field>
		</record>
		
		<record id="mmr_product_form" model="ir.ui.view">
			<field name="name">mmr.product.form</field>
			<field name="model">mmr.product</field>
			<field name="arch" type="xml">
				<form string="Product" version="7.0" >
					<header>
						<button name="%(report_example)d" string="Print" type="action"/>
					</header>
					<group>
						<field name="brand" />
						<field name="name" />
						<field name="unit" />
						<field name="minimumSellPrice" />
					</group>
				</form>
			</field>
		</record>
		
		<record id="mmr_brand_list" model="ir.ui.view">
			<field name="name">mmr.brand.list</field>
			<field name="model">mmr.brand</field>
			<field name="arch" type="xml">
				<tree string="Brand" version="7.0">
					<field name="name" />
					<field name="notes" />
				</tree>
			</field>
		</record>
		
		<record id="mmr_brand_form" model="ir.ui.view">
			<field name="name">mmr.brand.form</field>
			<field name="model">mmr.brand</field>
			<field name="arch" type="xml">
				<form string="Brand" version="7.0" >
					<group>
						<field name="name" />
						<field name="notes" />
					</group>
				</form>
			</field>
		</record>
		
	</data>
</openerp> 

And Menu named menu_master,

<openerp>
	<data>
		<record id="multi_action_master_mmr_product" model="ir.actions.act_window">
			<field name="name">Product</field>
			<field name="res_model">mmr.product</field>
			<field name="view_type">form</field>
			<field name="view_mode">tree,form</field>
		</record>
								
		<menuitem id="mmr_menu" name="MMR" sequence="111" groups="base.group_user"/>
		
		<menuitem id="mmr_menu_product" name="Product" parent="mmr_menu" sequence="1" />
			<menuitem id="multi_menu_master_product" action="multi_action_master_mmr_product" name="Product" parent="mmr_menu_product" sequence="1" />
			
	</data>
</openerp> 

I also have created xml containing report template, i named the file reportExample.xml and placed it in view folder

<?xml version="1.0" encoding="utf-8"?>
<!--Custom report.-->
<openerp>
<data>

<template id="report_example">
    <t t-call="report.external_layout">
        <div class="page">
            <div class="row">
                <h3>Title</h3>
            </div>
        </div>
    </t>
</template>

</data>
</openerp> 

Then I also create xml named MMR_report.xml, containing

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <report 
            id="custom_report_example"
            model="mmr.product"
            string="Example"
            report_type="qweb-pdf"
            name="mmr.report_example"
            attachment_use="False"
            file="mmr.report_example"
        />
    </data>
</openerp> 

Also, I already noticed __openerp__ file about my new report

 'update_xml': [  
       'view/reportExample.xml',          
       'view/master.xml',
       'menu/menu_master.xml',           
	],  

As you can see, I already insert button which I expect to show my custom report page when i pressed it. Unfortunately it doesn't work. Can someone explain what wrong with it?