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<ManualTopic ID="/baanerp/tc/onlinemanual/000350" xml:lang="en">
	<Header>
		<Title xmlns:ssa="http://www.ssaglobal.com" xmlns:HTML="http://www.w3.org/TR/REC-html40">To use efficiency factors</Title>
		<Keyword><Level1>Calendars</Level1>
		</Keyword>
		<Keyword><Level1>Lead-time offsetting</Level1>
		</Keyword>
		<Keyword><Level1>Capacity planning</Level1>
		</Keyword>
	</Header>
	<GeneralSection><Paragraph>SSA ERP uses <Link href="/baanerp/tc/glossary/glossary#000368" role="glossary">efficiency factors</Link> to take into account variable daily capacity for lead-time calculation.</Paragraph>
		<Paragraph>Various reasons can exist for variability in daily capacity, such as reduction of work force in the holiday season, or hiring extra work force in busy periods, which in practice means that there is more or less available plan time on a specific day.</Paragraph>
		<List><ListIntro>You can define efficiency factors when you set up a calendar in the <GUIRef href="/baanerp/tc/ccp" role="module">Calendars and Periods</GUIRef> module of <GUIRef href="/baanerp/tc" role="package">Common Data</GUIRef>. Per <Link href="/baanerp/tc/glossary/glossary#TimeIntervTy.tc" role="glossary">working hours type</Link> you can specify an efficiency factor, which SSA ERP uses as a default. You can further overwrite this default value in one of the following sessions:</ListIntro>
			<ListItem><GUIRef href="/baanerp/tc/ccp/tcccp0140m000" role="session">Standard Calendar (tcccp0140m000)</GUIRef>.</ListItem>
			<ListItem><GUIRef href="/baanerp/tc/ccp/tcccp0142m000" role="session">Calendar Recurrence Working Hours (tcccp0142m000)</GUIRef>.</ListItem>
			<ListItem><GUIRef href="/baanerp/tc/ccp/tcccp0120m000" role="session">Calendar Working Hours (tcccp0120m000)</GUIRef>.</ListItem>
		</List>
		<GeneralSection><ProcedureSection><SectionTitle>Lead-time offsetting</SectionTitle>
				<Steps><StepsIntro>With the introduction of efficiency factors, the lead-time calculation process in <GUIRef href="/baanerp/cp" role="package">Enterprise Planning</GUIRef> consists of the following four steps:</StepsIntro>
					<Step><StepTitle>Determine the end date/start date</StepTitle>
						<Paragraph>Dependent on whether you want to plan forward or backward, SSA ERP retrieves data concerning the start date or the end date from the <GUIRef href="/baanerp/tc/ccp/tcccp0120m000" role="session">Calendar Working Hours (tcccp0120m000)</GUIRef> session. Each line in the <GUIRef href="/baanerp/tc/ccp/tcccp0120m000" role="session">Calendar Working Hours (tcccp0120m000)</GUIRef> session contains details about the available planning time in seconds or hours (depending on the setting of the <GUIRef href="" role="manual">Time Unit</GUIRef> field in the <GUIRef href="/baanerp/tc/mcs/tcmcs0500m000" role="session">Base Units (tcmcs0500m000)</GUIRef> session), and to start, SSA ERP subtracts the available planning time on the start date/end date from the total lead-time.</Paragraph>
						<Paragraph>Next, SSA ERP repeats this action on the date following the start date in case of forward planning, or on the date preceding the end date in case of backward planning, until it comes across the date on which the remaining total lead time is less than the total available planning time. This is the end date/start date.</Paragraph>
					</Step>
					<Step><StepTitle>Determine the efficiency factor</StepTitle>
						<Paragraph>To calculate the exact time on the end date/start date, SSA ERP must determine the efficiency factor that is valid on that date. The formula to calculate the efficiency factor is:</Paragraph>
						<Formula><Paragraph UserLevel="Novice" UserType="Taskuser">Available seconds in day / (end time - start time ) * 3600</Paragraph>
						</Formula>
					</Step>
					<Step><StepTitle>Convert the remaining lead time</StepTitle>
						<Paragraph>When SSA ERP knows the efficiency factor, it can convert the remaining lead time (planning time) to actual hours according to the following formula:</Paragraph>
						<Formula><Paragraph UserLevel="Novice" UserType="Taskuser">(remaining) planning hours / efficiency factor </Paragraph>
						</Formula>
					</Step>
					<Step><StepTitle>Determine the end time</StepTitle>
						<Paragraph>Next, SSA ERP can add the remaining actual hours to the start date of the day on which the end time is due to fall, in case of forward planning. In case of backward planning, SSA ERP subtracts the actual remaining hours from the end date on which the start date is due to fall.</Paragraph>
						<Paragraph>To calculate the exact time on the end date/start date, SSA ERP must determine the efficiency factor that is valid on that date. The formula to calculate the efficiency factor is:</Paragraph>
						<Formula><Paragraph UserLevel="Novice" UserType="Taskuser">available seconds in day / (end time - start time) * 3600 </Paragraph>
						</Formula>
						<Paragraph>When SSA ERP knows the efficiency factor, it can convert the remaining lead time (planning time) to actual hours according to the following formula:</Paragraph>
						<Formula><Paragraph UserLevel="Novice" UserType="Taskuser">(remaining) planning hours / efficiency factor</Paragraph>
						</Formula>
					</Step>
				</Steps>
			</ProcedureSection>
		</GeneralSection>
		<ExampleSection><SectionTitle>Example</SectionTitle>
			<Paragraph>Suppose you have a lead time of 10 hours and, in a forward planning situation, the planned start date is 01/01/2001. Two calendar lines exist which contain the following details:</Paragraph>
			<TABLE border="1"><THEAD><TR><TD>Date</TD>
						<TD>Start time</TD>
						<TD>End time</TD>
						<TD>Efficiency factor</TD>
						<TD>Cumulative time</TD>
					</TR>
				</THEAD>
				<TBODY><TR><TD>01/01/2001</TD>
						<TD>09:00</TD>
						<TD>17:00</TD>
						<TD>1</TD>
						<TD>8 hours</TD>
					</TR>
					<TR><TD>02/01/2001</TD>
						<TD>17:00</TD>
						<TD>23:00</TD>
						<TD>0.8</TD>
						<TD>4.8 hours</TD>
					</TR>
				</TBODY>
			</TABLE>
			<Paragraph>If SSA ERP knows the end date/start date, it performs lead-time offsetting as follows:</Paragraph>
			<Paragraph><Emphasis>Step 1:</Emphasis> Total lead-time minus the cumulative time of the start date: 10 - 8 = 2.</Paragraph>
			<Paragraph>The end date is due to fall on 02/01/2001, because the remaining lead-time (2 hours) is less than the cumulative time on 02/01/2001 (4.8 hours).</Paragraph>
			<Paragraph><Emphasis>Step 2:</Emphasis>SSA ERP applies the following formula to determine the efficiency factor:</Paragraph>
			<Formula><Paragraph UserLevel="Novice" UserType="Taskuser">available seconds in day / (end time - start time) * 3600 </Paragraph>
			</Formula>
			<Paragraph>In the example, this formula results in an efficiency factor of:</Paragraph>
			<Formula><Paragraph UserLevel="Novice" UserType="Taskuser">(4.8 * 3600) / (23:00 - 17:00) * 3600 = 17280 / 21600 = 0.8 </Paragraph>
			</Formula>
			<Paragraph><Emphasis>Step 3:</Emphasis> The conversion of the (remaining) lead-time to actual hours is:</Paragraph>
			<Formula><Paragraph UserLevel="Novice" UserType="Taskuser"> (remaining) lead time / efficiency factor = 2.00 / 0.8 = 2.5 </Paragraph>
			</Formula>
			<Paragraph>So the remaining lead-time amounts to 2 hours and 30 minutes.</Paragraph>
			<Paragraph><Emphasis>Step 4:</Emphasis>SSA ERP can now determine the end time by adding the remaining lead time to the actual start time on the end date:</Paragraph>
			<Formula><Paragraph UserLevel="Novice" UserType="Taskuser">17:00 + 2:30 = 19:30 </Paragraph>
			</Formula>
		</ExampleSection>
	</GeneralSection>
</ManualTopic>
