<?xml version="1.0" encoding="utf-8"?>
<ManualTopic ID="/baanerp/cp/onlinemanual/000079" xml:lang="en">
	<Header>
		<Title xmlns:ssa="http://www.ssaglobal.com" xmlns:HTML="http://www.w3.org/TR/REC-html40">Algorithm for demand forecasting</Title>
		<Keyword><Level1>Algorithm for demand forecasting</Level1>
		</Keyword>
		<Keyword><Level1>Demand forecasting</Level1>
			<Level2>algorithm</Level2>
		</Keyword>
	</Header>
	<GeneralSection><Paragraph>SSA ERP calculates the <Link href="/baanerp/cp/glossary/glossary#000015" role="glossary">demand forecast</Link> on the basis of the historical demand with the following algorithm.</Paragraph>
		<ProcedureList><ListIntro>The main steps of the calculation are:</ListIntro>
			<ListItem>Retrieve the demand history.</ListItem>
			<ListItem>Check the demand history.</ListItem>
			<ListItem>Determine the trend factor.</ListItem>
			<ListItem>Determine the seasonal pattern.</ListItem>
			<ListItem>Forecast the demand.</ListItem>
			<ListItem>Compute forecast errors and the seasonal correlation.</ListItem>
			<ListItem>Convert the demand forecast to plan periods.</ListItem>
		</ProcedureList>
		<Paragraph>In the following sections, each calculation step will be explained.</Paragraph>
	</GeneralSection>
	<GeneralSection><SectionTitle>1. Retrieve the demand history</SectionTitle>
		<Paragraph>The demand forecast is based on the historical demand data in the time period between the start date of the scenario and the current plan period.</Paragraph>
		<List><ListIntro>Historical demand data consists of the following fields in the <GUIRef href="/baanerp/cp/rmp/cprmp2101m000" role="session">Item Master Plan (cprmp2101m000)</GUIRef> session or the <GUIRef href="/baanerp/cp/dsp/cpdsp5130m000" role="session">Channel Master Plan (cpdsp5130m000)</GUIRef> session:</ListIntro>
			<ListItem><GUIRef href="/baanerp/cp/rmp/cprmp2101m000#cprmp300.srec" role="formfield">Sched Prod Receipts</GUIRef>
			</ListItem>
			<ListItem><GUIRef href="/baanerp/cp/rmp/cprmp2101m000#cprmp300.idel" role="formfield">Internal Deliveries</GUIRef> (*)</ListItem>
		</List>
		<Paragraph>(*) Only taken into account if the <GUIRef href="/baanerp/cp/rpd/cprpd1100m000#cprpd100.depd" role="formfield">Dependent Demand Forecast</GUIRef> check box in the <GUIRef href="/baanerp/cp/rpd/cprpd1100m000" role="session">Items - Planning (cprpd1100m000)</GUIRef> session is selected.</Paragraph>
		<Paragraph>SSA ERP converts the demand history in the current master plan from <Link href="/baanerp/cp/glossary/glossary#000109" role="glossary">plan periods</Link> to fixed-length forecast periods, based on the <GUIRef href="/baanerp/cp/rpd/cprpd4100m000#cprpd400.pldf" role="formfield">Forecast Period Length</GUIRef> field in the <GUIRef href="/baanerp/cp/rpd/cprpd4100m000" role="session">Scenarios (cprpd4100m000)</GUIRef> session. See <Link href="/baanerp/cp/onlinemanual/000132" role="manual">To distribute master-plan quantities over calendar days</Link>.</Paragraph>
	</GeneralSection>
	<GeneralSection><SectionTitle>Adjusting for nonworking days</SectionTitle>
		<Paragraph>SSA ERP increases the actual demand with a fictitious demand for nonworking days, such as holidays, to prevent demand fluctuations. The fictitious demand is equal to the average demand in the forecast period.</Paragraph>
		<Paragraph>The calendar of the item's enterpise unit (see the <GUIRef href="/baanerp/cp/rpd/cprpd1100m000" role="session">Items - Planning (cprpd1100m000)</GUIRef> session) defines which days are <Link href="/baanerp/cp/glossary/glossary#000064" role="glossary">workdays</Link>. SSA ERP reverses the adjustment in the final step of the calculation, when the demand forecast is converted back to plan periods.</Paragraph>
	</GeneralSection>
	<GeneralSection><SectionTitle>2. Check demand history</SectionTitle>
		<Paragraph>After SSA ERP retrieves the available demand history for a plan item, it checks whether the demand history is sufficient to perform a demand forecast. SSA ERP counts the forecast periods from the first period with actual demand up to the current period.</Paragraph>
		<Paragraph>The criteria for the minimum number of forecast periods depend on the applied forecast method and the seasonal cycle time. If the history data does not suffice, SSA ERP aborts the demand forecast calculation, and reports the reason.</Paragraph>
	</GeneralSection>
	<GeneralSection><SectionTitle>3. Determine trend factor</SectionTitle>
		<Paragraph>Determination of the trend factor depends on:</Paragraph>
		<List><ListItem><GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.toti" role="formfield">Type of Trend Influence</GUIRef>
			</ListItem>
			<ListItem><GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.tosi" role="formfield">Type of Seasonal Influence</GUIRef>
			</ListItem>
		</List>
		<Paragraph>These parameters are located in the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000" role="session">Plan Items - Forecast Settings (cpdsp1110m000)</GUIRef> session.</Paragraph>
		<Paragraph>In the following part of this text, it is assumed that the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.aufp" role="field">Automatic Update of Forecast Parameters</GUIRef> check box is cleared. The effect of the automatic update of forecast parameters is described later.</Paragraph>
	</GeneralSection>
	<GeneralSection><SectionTitle>Linear</SectionTitle>
		<Paragraph>If the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.toti" role="formfield">Type of Trend Influence</GUIRef> field is <GUIRef href="/baanerp/cp/domains/rpd.toti#linear" role="enum">Linear</GUIRef>, the trend influence can be described by means of the following formula:</Paragraph>
		<Formula><Paragraph UserLevel="Novice" UserType="Taskuser"> FD(t) = CS + TF *	t </Paragraph>
		</Formula>
		<Paragraph>Where CS = constant demand TF = trend factor FD(t) = the demand forecast for period t</Paragraph>
		<Paragraph>SSA ERP calculates the trend factor (TF) and the constant demand (CS), based on a first degree polynom by means of polynomial regression. See <Link href="/baanerp/cp/onlinemanual/000108" role="manual">Principle of polynomial regression</Link>. If there is a seasonal cycle, SSA ERP determines the first degree polynom on the basis of a whole number of seasonal cycles.</Paragraph>
	</GeneralSection>
	<GeneralSection><SectionTitle>Progressive</SectionTitle>
		<Paragraph>If the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.toti" role="formfield">Type of Trend Influence</GUIRef> field is <GUIRef href="/baanerp/cp/domains/rpd.toti#progressive" role="enum">Progressive</GUIRef>, the trend influence can be described by means of the following formula:</Paragraph>
		<Formula><Paragraph UserLevel="Novice" UserType="Taskuser"> FD(t) = BS * (TF ^ (t-1)) </Paragraph>
		</Formula>
		<Paragraph>Where BS = base demand (the estimated demand for period 1) TF = trend factor FD(t) = the demand forecast for period t</Paragraph>
	</GeneralSection>
	<GeneralSection><List><ListIntro>SSA ERP determines the trend factor (TF) and the base demand (BS) with the following calculation:</ListIntro>
			<ListItem>The calculation is based on the first and the last period with demand history. If a seasonal influence exists, two periods, which lie a whole number of seasonal cycles apart, are selected.</ListItem>
			<ListItem>The estimated demand of the selected periods is determined by using a second degree polynom. SSA ERP determines this polynom with polynomial regression. If a second degree polynom cannot be determined, the actual demand in the first and last period with demand history is used instead of the estimated demand.</ListItem>
			<ListItem>The trend factor and base demand are calculated as follows:</ListItem>
		</List>
		<Figure><HTML:IMG SRC="../images/nt_graph_000079.gif" width="144" height="108" xmlns:ssa="http://www.ssaglobal.com" xmlns:HTML="http://www.w3.org/TR/REC-html40"/><FigLegend><LegendEntry><Symbol>BS</Symbol>
					<Desc>base demand</Desc>
				</LegendEntry>
				<LegendEntry><Symbol>TF</Symbol>
					<Desc>trend factor</Desc>
				</LegendEntry>
				<LegendEntry><Symbol>ED(t1)</Symbol>
					<Desc>the estimated demand in the first period with demand history</Desc>
				</LegendEntry>
				<LegendEntry><Symbol>ED(t2)</Symbol>
					<Desc>the estimated demand in the last period with demand history</Desc>
				</LegendEntry>
				<LegendEntry><Symbol>n</Symbol>
					<Desc>number of demand history periods minus 1</Desc>
				</LegendEntry>
			</FigLegend>
		</Figure>
	</GeneralSection>
	<GeneralSection><SectionTitle>Not Applicable</SectionTitle>
		<Paragraph>If the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.toti" role="formfield">Type of Trend Influence</GUIRef> field is <GUIRef href="/baanerp/cp/domains/rpd.toti#not.in.use" role="enum">Not Applicable</GUIRef>, the trend factor is not used.</Paragraph>
	</GeneralSection>
	<GeneralSection><Note><SectionTitle>Note</SectionTitle>
			<List><ListIntro>SSA ERP checks whether a trend is present. SSA ERP reports the following situations without actually changing the type of trend influence:</ListIntro>
				<ListItem>The <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.toti" role="formfield">Type of Trend Influence</GUIRef> field is <GUIRef href="/baanerp/cp/domains/rpd.toti#linear" role="enum">Linear</GUIRef> or <GUIRef href="/baanerp/cp/domains/rpd.toti#progressive" role="enum">Progressive</GUIRef>, but no trend can be detected.</ListItem>
				<ListItem>The <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.toti" role="formfield">Type of Trend Influence</GUIRef> field is <GUIRef href="/baanerp/cp/domains/rpd.toti#not.in.use" role="enum">Not Applicable</GUIRef>, but a trend is detected anyway.</ListItem>
			</List>
		</Note>
	</GeneralSection>
	<GeneralSection><SectionTitle>Automatic Update of Forecast Parameters</SectionTitle>
		<Paragraph>If the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.aufp" role="formfield">Automatic Update of Forecast Parameters</GUIRef> check box in the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000" role="session">Plan Items - Forecast Settings (cpdsp1110m000)</GUIRef> session is selected, SSA ERP performs an automatic trend detection.</Paragraph>
		<Paragraph>If the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.toti" role="field">Type of Trend Influence</GUIRef> field is <GUIRef href="/baanerp/cp/domains/rpd.toti#linear" role="enum">Linear</GUIRef> or <GUIRef href="/baanerp/cp/domains/rpd.toti#not.in.use" role="enum">Not Applicable</GUIRef>, SSA ERP calculates a trend factor according to the method for linear trends. If the trend factor is found to be zero, SSA ERP sets the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.toti" role="field">Type of Trend Influence</GUIRef> field to <GUIRef href="/baanerp/cp/domains/rpd.toti#not.in.use" role="enum">Not Applicable</GUIRef>.</Paragraph>
		<Paragraph>SSA ERP reports any automatic change of the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.toti" role="field">Type of Trend Influence</GUIRef> field.</Paragraph>
	</GeneralSection>
	<GeneralSection><SectionTitle>4. Determine seasonal pattern</SectionTitle>
		<Paragraph>A seasonal pattern is defined by a series of seasonal factors: one seasonal factor for each forecast period in a seasonal cycle.</Paragraph>
		<Paragraph>If you specified a fixed seasonal pattern in the <GUIRef href="/baanerp/tc/ibd/tcibd2100s000#tcibd200.cspd" role="field">Seasonal Pattern for Forecast</GUIRef> field in the <GUIRef href="/baanerp/tc/ibd/tcibd2500m000" role="session">Items - Ordering (tcibd2500m000)</GUIRef> session, SSA ERP determines the seasonal factor for each period based on the seasonal factors defined at the <Link href="/baanerp/cp/glossary/glossary#000027" role="glossary">execution level</Link>. If the <GUIRef href="/baanerp/tc/ibd/tcibd2100s000#tcibd200.cspd" role="field">Seasonal Pattern for Forecast</GUIRef> field is empty, SSA ERP determines the seasonal pattern on the basis of the trend-adjusted demand history.</Paragraph>
		<Paragraph>The determination of the seasonal pattern based on the demand history depends on the following fields in the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000" role="session">Plan Items - Forecast Settings (cpdsp1110m000)</GUIRef> session:</Paragraph>
		<List><ListItem><GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.tosi" role="field">Type of Seasonal Influence</GUIRef>
			</ListItem>
			<ListItem><GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.sctm" role="field">Seasonal Cycle Time</GUIRef>
			</ListItem>
			<ListItem><GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.aufp" role="field">Automatic Update of Forecast Parameters</GUIRef>
			</ListItem>
		</List>
		<Paragraph>If the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.aufp" role="field">Automatic Update of Forecast Parameters</GUIRef> check box is selected, SSA ERP can update the following fields automatically:</Paragraph>
		<List><ListItem><GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.tosi" role="field">Type of Seasonal Influence</GUIRef>
			</ListItem>
			<ListItem><GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.sctm" role="field">Seasonal Cycle Time</GUIRef>
			</ListItem>
		</List>
		<Paragraph>The seasonal factors are calculated as follows:</Paragraph>
		<Formula><Paragraph UserLevel="Novice" UserType="Taskuser">(1) TD(t) = AV</Paragraph>
		</Formula>
		<Formula><Paragraph UserLevel="Novice" UserType="Taskuser">(2) TD(t) = CS + TF * t</Paragraph>
		</Formula>
		<Formula><Paragraph UserLevel="Novice" UserType="Taskuser">(3) TD(t) = BS * TF ^ (t-1)</Paragraph>
		</Formula>
		<TABLE border="1"><TBODY><TR><TD>(1)</TD>
					<TD width="274">without seasonal influence</TD>
				</TR>
				<TR><TD>(2)</TD>
					<TD width="274">with linear trend influence</TD>
				</TR>
				<TR><TD>(3)</TD>
					<TD width="274">with a progressive trend influence</TD>
				</TR>
				<TR><TD>(*)</TD>
					<TD width="274">The average demand is determined as the sum of the historical demand figures per period divided by the number of periods with demand history.</TD>
				</TR>
			</TBODY>
		</TABLE>
		<Paragraph>Where:</Paragraph>
		<TABLE border="1"><TBODY><TR><TD>TD(t)</TD>
					<TD>the trend based demand</TD>
				</TR>
				<TR><TD>AV</TD>
					<TD>average demand</TD>
				</TR>
				<TR><TD>CS</TD>
					<TD>constant demand</TD>
				</TR>
				<TR><TD>BS</TD>
					<TD>the estimated demand for period 1</TD>
				</TR>
				<TR><TD>TF</TD>
					<TD>trend factor</TD>
				</TR>
			</TBODY>
		</TABLE>
	</GeneralSection>
	<GeneralSection><SectionTitle>Constant</SectionTitle>
		<Paragraph>If the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.tosi" role="formfield">Type of Seasonal Influence</GUIRef> field is <GUIRef href="/baanerp/cp/domains/rpd.tosi#constant" role="enum">Constant</GUIRef>, the seasonal factor is equal to the actual demand reduced by the trend-adjusted average demand for the relevant period. This is calculated as follows:</Paragraph>
		<Formula><Paragraph UserLevel="Novice" UserType="Taskuser"> SF(t) = AD(t) -	TD(t) </Paragraph>
		</Formula>
		<Paragraph>Where:</Paragraph>
		<TABLE border="1"><TBODY><TR><TD>SF(t)</TD>
					<TD>the seasonal factor for period t</TD>
				</TR>
				<TR><TD>AD(t)</TD>
					<TD>the actual demand for period t</TD>
				</TR>
				<TR><TD>TD(t)</TD>
					<TD>the trend based demand for period t</TD>
				</TR>
			</TBODY>
		</TABLE>
	</GeneralSection>
	<GeneralSection><SectionTitle>Progressive</SectionTitle>
		<Paragraph>If the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.tosi" role="formfield">Type of Seasonal Influence</GUIRef> field is <GUIRef href="/baanerp/cp/domains/rpd.tosi#progressive" role="enum">Progressive</GUIRef>, the seasonal factor is equal to the actual demand divided by the trend-adjusted average demand for the period concerned. This is calculated as follows:</Paragraph>
		<Formula><Paragraph UserLevel="Novice" UserType="Taskuser"> SF(t) = AD(t) /	TD(t) </Paragraph>
		</Formula>
		<Paragraph>Where:</Paragraph>
		<TABLE border="1"><TBODY><TR><TD>SF(t)</TD>
					<TD>the seasonal factor for period t</TD>
				</TR>
				<TR><TD>AD(t)</TD>
					<TD>the actual demand for period t</TD>
				</TR>
				<TR><TD>TD(t)</TD>
					<TD>the trend based demand for period t</TD>
				</TR>
			</TBODY>
		</TABLE>
		<Paragraph>The above seasonal factor is computed as an average seasonal factor for each period.</Paragraph>
	</GeneralSection>
	<GeneralSection><Note><SectionTitle>Note</SectionTitle>
			<List><ListIntro>SSA ERP checks whether a seasonal pattern is present. SSA ERP reports the following situations:</ListIntro>
				<ListItem>The <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.tosi" role="formfield">Type of Seasonal Influence</GUIRef> field is <GUIRef href="/baanerp/cp/domains/rpd.tosi#constant" role="enum">Constant</GUIRef> or <GUIRef href="/baanerp/cp/domains/rpd.tosi#progressive" role="enum">Progressive</GUIRef>, but no seasonal pattern can be detected.</ListItem>
				<ListItem>The <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.tosi" role="formfield">Type of Seasonal Influence</GUIRef> field is <GUIRef href="/baanerp/cp/domains/rpd.tosi#not.in.use" role="enum">Not Applicable</GUIRef>, but a seasonal pattern is detected anyway.</ListItem>
			</List>
		</Note>
	</GeneralSection>
	<GeneralSection><Paragraph>A seasonal pattern is assumed to be present, if the value of the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.scrf" role="field">Seasonal Correlation Factor</GUIRef> field is at least 0.8.</Paragraph>
	</GeneralSection>
	<GeneralSection><Paragraph>If the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.aufp" role="field">Automatic Update of Forecast Parameters</GUIRef> check box is selected and one of the above-mentioned situations presents itself, SSA ERP changes the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.tosi" role="field">Type of Seasonal Influence</GUIRef> field accordingly.</Paragraph>
	</GeneralSection>
	<GeneralSection><SectionTitle>Automatic Update of Forecast Parameters</SectionTitle>
		<Paragraph>If the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.aufp" role="formfield">Automatic Update of Forecast Parameters</GUIRef> check box in the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000" role="session">Plan Items - Forecast Settings (cpdsp1110m000)</GUIRef> session is selected, SSA ERP performs an automatic seasonal pattern detection.</Paragraph>
		<Paragraph>If the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.tosi" role="field">Type of Seasonal Influence</GUIRef> field is <GUIRef href="/baanerp/cp/domains/rpd.tosi#constant" role="enum">Constant</GUIRef> or <GUIRef href="/baanerp/cp/domains/rpd.tosi#not.in.use" role="enum">Not Applicable</GUIRef>, SSA ERP calculates a seasonal pattern according to the method for Constant patterns. If no seasonal pattern is detected, SSA ERP sets the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.tosi" role="field">Type of Seasonal Influence</GUIRef> field to <GUIRef href="/baanerp/cp/domains/rpd.tosi#not.in.use" role="enum">Not Applicable</GUIRef>.</Paragraph>
		<Paragraph>If the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.tosi" role="field">Type of Seasonal Influence</GUIRef> field is <GUIRef href="/baanerp/cp/domains/rpd.tosi#progressive" role="enum">Progressive</GUIRef>, SSA ERP calculates a seasonal pattern according to the method for Progressive patterns. If no pattern is detected, SSA ERP sets the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.tosi" role="field">Type of Seasonal Influence</GUIRef> field to <GUIRef href="/baanerp/cp/domains/rpd.tosi#not.in.use" role="enum">Not Applicable</GUIRef>.</Paragraph>
		<Paragraph>SSA ERP reports any automatic change of the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.tosi" role="field">Type of Seasonal Influence</GUIRef>.</Paragraph>
	</GeneralSection>
	<GeneralSection><SectionTitle>5. Forecast the demand</SectionTitle>
		<Paragraph>SSA ERP applies the forecast method that you specified in the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.fcmd" role="field">Forecast Method</GUIRef> field in the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000" role="session">Plan Items - Forecast Settings (cpdsp1110m000)</GUIRef> session.</Paragraph>
	</GeneralSection>
	<GeneralSection><SectionTitle>6. Compute forecast errors and seasonal correlation</SectionTitle>
		<Paragraph>After SSA ERP forecasts the demand for a plan item, it determines the following error and correlation information:</Paragraph>
		<List><ListItem><GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.afce" role="field">Average Forecast Error</GUIRef>
			</ListItem>
			<ListItem><GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.madf" role="field">Mean Absolute Deviation</GUIRef>
			</ListItem>
			<ListItem><GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.mrdf" role="field">Mean Relative Deviation</GUIRef>
			</ListItem>
			<ListItem><GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.sdev" role="field">Standard Deviation</GUIRef>
			</ListItem>
			<ListItem><GUIRef href="/baanerp/cp/dsp/cpdsp1110m000#cpdsp110.scrf" role="field">Seasonal Correlation Factor</GUIRef>
			</ListItem>
		</List>
		<Paragraph>This information is displayed in the <GUIRef href="/baanerp/cp/dsp/cpdsp1110m000" role="session">Plan Items - Forecast Settings (cpdsp1110m000)</GUIRef> session.</Paragraph>
	</GeneralSection>
	<GeneralSection><SectionTitle>7. Convert demand forecast to plan periods</SectionTitle>
		<Paragraph>SSA ERP converts the computed demand forecast for the forecast periods from a fixed period length to plan periods with a variable period length. This process is the reverse of the first step Retrieve demand history).</Paragraph>
	</GeneralSection>
	<GeneralSection ID="1"><SectionTitle>Adjusting for nonworking days</SectionTitle>
		<Paragraph>SSA ERP treats workdays and nonworking days differently. The calendar of the company calendar provider defines which days are <Link href="/baanerp/cp/glossary/glossary#000064" role="glossary">workdays</Link>. Concretely, this means that a demand forecast for a day with zero available capacity is ignored, so that no demand forecast is generated for public holidays and other days off.</Paragraph>
	</GeneralSection>
	<RelatedTopics><SectionTitle>Related topics</SectionTitle>
		<RelTopic><Link href="/baanerp/cp/onlinemanual/000107" role="manual">To compute the demand forecast</Link>
		</RelTopic>
		<RelTopic><Link href="/baanerp/cp/onlinemanual/000108" role="manual">Principle of polynomial regression</Link>
		</RelTopic>
		<RelTopic><Link href="/baanerp/cp/onlinemanual/000321" role="manual">Forecasting methods</Link>
		</RelTopic>
		<RelTopic><Link href="/baanerp/cp/onlinemanual/000113" role="manual">Forecast errors and seasonal correlation</Link>
		</RelTopic>
	</RelatedTopics>
</ManualTopic>
