odoo/addons/hr_timesheet_sheet/hr_timesheet_workflow.xml

<?xml version="1.0" ?>
<terp>
	<data>

		<!-- Roles definition -->

		<record model="res.roles" id="HR">
			<field name="name">Timesheets validation</field>
		</record>

		<!-- Workflow definition -->

		<record model="workflow" id="wkf_timesheet">
			<field name="name">hr_timesheet_sheet.sheet</field>
			<field name="osv">hr_timesheet_sheet.sheet</field>
			<field name="on_create">True</field>
		</record>

		<record model="workflow.activity" id="act_new">
			<field name="wkf_id" ref="wkf_timesheet" />
			<field name="name">new</field>
			<field name="kind">function</field>
			<field name="action">write({'state':'new'})</field>
			<field name="flow_start">True</field>
		</record>
		<record model="workflow.activity" id="act_draft">
			<field name="wkf_id" ref="wkf_timesheet" />
			<field name="name">draft</field>
			<field name="kind">function</field>
			<field name="action">write({'state':'draft'})</field>
		</record>
		<record model="workflow.activity" id="act_confirm">
			<field name="wkf_id" ref="wkf_timesheet" />
			<field name="name">confirm</field>
			<field name="kind">function</field>
			<field name="action">write({'state':'confirm'})</field>
		</record>
		<record model="workflow.activity" id="act_done">
			<field name="wkf_id" ref="wkf_timesheet" />
			<field name="name">done</field>
			<field name="kind">function</field>
			<field name="action">write({'state':'done'})</field>
			<field name="flow_stop">True</field>
		</record>

		<record model="workflow.transition" id="t0">
			<field name="act_from" ref="act_new"/>
			<field name="act_to" ref="act_draft"/>
		</record>
		<record model="workflow.transition" id="t1">
			<field name="act_from" ref="act_draft" />
			<field name="act_to" ref="act_confirm" />
			<field name="signal">confirm</field>
		</record>
		<record model="workflow.transition" id="t2">
			<field name="act_from" ref="act_confirm" />
			<field name="act_to" ref="act_done" />
			<field name="signal">done</field>
			<field name="role_id" ref="HR"/>
		</record>
		<record model="workflow.transition" id="t3">
			<field name="act_from" ref="act_confirm" />
			<field name="act_to" ref="act_draft" />
			<field name="signal">cancel</field>
			<field name="role_id" ref="HR"/>
		</record>
	</data>
</terp>