XPath for Cost Based Estimating

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XPath for Cost Based Estimating

• Fusion 08
• Duncan Seibert

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Introduction

• XPath, as implemented by ePace, provides the user
  with a tool to define a value for an operation
  that is custom to their shop. Typically the XPath
  expression is used to provide a quantity that is
  used as the basis for a table lookup or is
  multiplied by a flat rate to provide either time
  or material usage.

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Abstract

• XPath is an expression language that allows the
  processing of values conforming to the data model
  defined in XQuery/XPath Data Model (XDM). The
  data model provides a tree representation of XML
  data sources as well as atomic values such as
  integers, strings, and booleans, and sequences
  that may contain both references to nodes in an
  XML data source and atomic values. The result of
  an XPath expression may be a selection of nodes
  from the input data sources, or an atomic value,
  or more generally, any sequence allowed by the
  data model. The name of the language derives from
  its most distinctive feature, the path
  expression, which provides a means of hierarchic
  addressing of the nodes in an XML tree.

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Session Contents

• 1. Determine what the calculation needs to do.
• 2. Determine field names.
• 3. Determine the data type of the result field.
• 4. Determine how you will cost your operation
  based on the data type.
• 5. Find your fields relative to the current
  object.
• 6. Write your expression in simple terms.
• 7. Write your expression in XPath.
• 8. Test your expression.
• 9. Enter your expression into ePace.
• 10. Use your expression.
• 11. Syntax.
• 12. Examples.

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1. Determine what the calculation needs to do.

• The first step is to determine what the formula
  needs to accomplish.
• Determine which fields hold reference values and
  what conditions need to be met first.
• Then determine the formula to arrive at the
  desired results.

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1. Determine what the calculation needs to do.

• The first step is to determine what the formula
  needs to accomplish. Determine which fields hold
  reference values and what conditions need to be
  met first. Then determine the formula to arrive
  at the desired results.
• Example
• To preflight a file, allow 15 minutes to review
  the job jacket, create a job directory on the
  storage server, transfer the file into the
  director and open the file in preflight software.
  Then allow 6 seconds per page to check the
  preflight, 10 pages per minute, 600 per hour.
• Formula .25 (number of pages / 600). Result
  is in decimal hours.

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2. Determine field names.

• There are two way to determine the names of the
  fields to use.

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2. Determine field names.

• There are two way to determine the names of the
  fields to use.
• One is to go to Administration -gt System
  Configuration -gt Object Model -gt Object Model
  Browser, select the target object, click on the
  Fields tab and find the fields you need.
• This will also show any Calculated Fields that
  may not appear on a screen but will make your
  statement easier.

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2. Determine field names.
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2. Determine field names.
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2. Determine field names.

• The other way is to open an estimate and go to
  details.
• Go to Administration -gt Toggle Debug Mode.
• This will show you the names of the fields in the
  Object Model (dataset).
• Drill into an operation like the one you will be
  describing, in our example a Prepress Operation.
• In the label area of the field of interest there
  will be a name. Hover over the field to show the
  information. It will appear as
• EstimatePrepressOp, expr ../_at_quantityOrdered

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2. Determine field names.
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2. Determine field names.

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2. Determine field names.

• Example
• For the preflight example, the fields we need are
  EstimateQuantity/_at_quantityOrdered,
  EstimateQuantity/_at_numPages, EstimatePart/_at_numSigs.
  
• In the Object Model Browser we find that the
  calculated field totalPages is _at_numPages
  _at_numSigs so that is what we will use.

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3. Determine the data type of the result field.

• Go to the Object Model Browser, select the target
  object, click on the Fields tab and find the Type
  of the field for your result.

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3. Determine the data type of the result field.

• Example
• EstimatePrepressOp object quantity field has a
  Type of Integer

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4. Determine how you will cost your operation
based on the data type.

• If the field is an integer, as quantity normally
  is, then you need to decide how to define your
  cost.
• In a Prepress Operation size you define hours per
  unit. Since XPath will return integer units, to
  get decimal time, times should be entered as 0.01
  hour per unit.

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4. Determine how you will cost your operation
based on the data type.

• Example
• Preflight operation size 99 x 99 Qty Up To
  99,999,999 Hours 0.01. XPath will return an
  integer value for units of hundredths of an hour.

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5. Find your fields relative to the current
object.

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5. Find your fields relative to the current object

• All field references in XPath are relative to the
  object of the result field.

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5. Find your fields relative to the current
object.

• Version 17 Cost Based Estimating Objects
• Company
• Estimate
• EstimatePart
• EstimateQuantity
• --------------- ----------------
  ------------------ ------------------
  -------------- --------------
• EstimatePrepressOp - EstimatePress -
  EstimateFinishingOp - EstimateOutsidePurch -
  EstimatePaper - EstimateInk - EstimateActivity
•  

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5. Find your fields relative to the current
object.

• We refer to these relationships as
• ??EstimatePart is a child of Estimate
• Estimate
• EstimatePart
• ??Estimate is the parent of EstimatePart
• ??EstimatePress is a sibling of EstimatePaper
• EstimatePress - EstimatePaper

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5. Find your fields relative to the current
object.

• The notation for these is
• ../ moves up a generation
• ../ltobject namegt moves to a sibling
• ltobject namegtcondition/ltobjectgt
• moves down a generation.

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5. Find your fields relative to the current
object.

• Examples
• If starting location is EstimatePrepressOp,
  parent is EstimateQuantity which is referred to
  as ../

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5. Find your fields relative to the current
object.

• Examples
• If starting location is EstimatePrepressOp,
  sizeDenominator (a field in company) is
  ../../../../_at_sizeDenominator
• The series of ../ refer, in sequence, to
  EstimateQuantity, then EstimatePart, then
  Estimate, then Company

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5. Find your fields relative to the current
object.

• Examples
• The condition is a way to select a field of a
  certain value and find data for that record.
  ../EstimatePress_at_pressIndicator0/_at_runSizeWidth
  refers to the sibling object EstimatePress with a
  specific record where pressIndicator 0 (primary
  press) and gets the runSizeWidth.

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5. Find your fields relative to the current
object.

• Examples
• To use this runSizeWidth, because we store sizes
  as integers, you need to divide the value by the
  system's size denominator so the expression would
  be
• (../EstimatePress_at_pressIndicator0/_at_runSizeWidth
  div ../../../../_at_sizeDenominator )?
• 38 would be stored as 608 if your
  sizeDenominator is 16.

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5. Find your fields relative to the current
object.

• Examples
• To get a value from an object outside of the tree
  shown above you use a notation like this
  (../EstimatePress_at_pressIndicator0/press/
• _at_gripperAllowance
• This would go to the sibling object,
  EstimatePress and select the primary press
  record, find the press on that record and return
  the gripper size.

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5. Find your fields relative to the current
object.

• Examples
• To get a value from an object outside of the tree
  by using a direct pointer, use syntax like this
  /InventoryItem_at_id'123Test'/_at_unitPrice
• If the object is a singleton (single record
  object like many setup objects), then the record
  selection is not necessary
• /EstimateSetup/_at_paperRoundingMode

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6. Write your expression in simple terms.

• Formula from Step 1 .25 (number of pages /
  600)?
• (¼ hour ( sum(numPages for all parts) / 600))
  100
• Remember, units are integers so to get 1/100 of
  an hour we must multiply by 100 to get units of
  .01 hours. 67 units times .01 hours .67 hours

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7. Write your expression in XPath.

• (.25 (sum(../../../EstimatePart/_at_totalPages)
  div 600)) 100
• Note
• To sum a value you must go to the parent and then
  sum the children. Here we go up to the Estimate
  and then refer to the EstimateParts. This will
  give us the total number of pages in all parts of
  the Estimate.

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8. Test your expression.

• Go to a sample estimate and manually calculate
  the result you want the system to return.
• In our example, we have a large perfect bound
  book of 1,566 pages.
• 1566 _at_ 600/hour 2.61 hours .25 2.86
• 2.86 hours 100 286 units

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8. Test your expression.

• Go to a sample estimate and get the object number
  as a data starting point.
• Example
• Go to your estimate detail Prepress tab and hover
  over a prepress operation drilldown icon. At the
  bottom of the browser window will appear a URL
  like http//epace.samplecompany.com/estimating/ob
  ject/EstimatePrepressOp/detail/5987

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8. Test your expression.

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8. Test your expression.

• Go to Administration -gt System Tools -gt XPath
  Evaluator.
• In Object Type enter the result's object.
• The primary key is the number at the end of the
  URL.
• The data type is from step 3.
• The Expression is the one you have written.
• Hit the Evaluate button and the Result should
  produce the value you expect.

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8. Test your expression.
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9. Enter your expression into ePace.

• Go to Administration -gt System Setup -gt
  Estimating -gt Misc Setup -gt Estimate Expression
  Setup.
• Add New Record.
• Enter a name, calculation type and copy your
  expression into the appropriate area, Expression
  Prepress or Expression Finishing.

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9. Enter your expression into ePace.
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10. Use your expression.

• Go to either a Prepress Workflow or a Finishing
  Operation.
• In the Quantity Calc Method select XPath
  Expression
• Choose your new expression in the Estimate
  Expression field

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10. Use your expression.
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11. Syntax

• ePace uses XPath 1.1 with custom extensions. If
  you get an XPath book, it may have version 2.0
  expressions which will not be understood by
  ePace.

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11. Syntax

• Any time an expression uses more than one
  operator, it is necessary to know what precedence
  is used. For XPath, this is (highest to lowest)
• ( ) 'grouping'
• 'filter'
• 'unary minus'
• div mod 'multiplication division modulus'
• - 'addition subtraction'
• ! lt lt gt gt 'relational (comparison)'
• 'union'
• not 'negation'
• and 'conjunction'
• or 'disjunction'
• Operators at the same precedence level are always
  evaluated left-to-right. Parentheses can be used
  to force the expression to evaluate in a
  different order than the default.

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11. Syntax

• Here are the some of the syntax statements that
  are currently available
• Comparison operators
• 'equal to'
• ! 'not equal to'
• gt 'greater than'
• gt 'greater than or equal to'
• lt 'less than'
• lt 'less than or equal to'
• Contains 'list of values contains test value'
• not 'reverses the true/false value of its
  argument'

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11. Syntax

• Here are the some of the syntax statements that
  are currently available
• Conditional Statement
• iif(ltvaluegt condition ltvaluegt, ltresultgt, ltelse
  resultgt)
• this may be nested

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11. Syntax

• Here are the some of the syntax statements that
  are currently available
• Arithmetic Statements
• 'plus'
• - 'minus'
• 'multiply by'
• div 'divide by'
• mod 'modulus'
• null-to-zero 'if _at_addHours returns null,
• null-to-zero(_at_addHours) returns 0'

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11. Syntax

• Here are the some of the syntax statements that
  are currently available
• Summary Statements
• sum(ltvalue listgt)?
• floor(ltvaluegt) result is rounded down toward
  negative infinity (negative numbers increase in
  absolute value)?
• ceiling(ltvaluegt) result is rounded up toward
  positive infinity
• round(ltvaluegt) result is rounded. lt .5 rounds
  down
• gt .5 rounds up
• count(ltvaluegt) result is number of records

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11. Syntax

• Here are the some of the syntax statements that
  are currently available
• String
• number(ltstring valuegt) 'result is a number. Use
  to convert string values before math'
• contains(string_1, string_2) 'returns true if
  string_1 contains string_2'
• concat(ltstring_1gt, ltstring_2gt, ltstring_3gt)
• 'concatenates strings'
• starts-with(ltstring_1gt,ltstring_2gt) 'returns true
  if string_1 starts with string_2, case
  sensitive'
• string(ltvaluegt) 'returns value as string, used
  to return a number as a string'

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11. Syntax

• Here are the some of the syntax statements that
  are currently available
• String
• string-length(ltstringgt) 'returns number of
  characters in the string'
• substring(ltstringgt,offset,length) 'returns a
  substring of ltlengthgt characters starting at
  ltoffsetgt '
• substring-after(ltstring_1gt,ltstring_2gt) 'returns
  the part of string_1 that follows the 1st
  occurance of string_2 '
• substring-before(ltstring_1gt,ltstring_2gt) 'like
  substring-after but returns the part before'
• current-date() 'returns the current date and can
  be used as a comparison in a iif statement'
• current-user() 'returns the current user'

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11. Syntax

• Here are the some of the syntax statements that
  are currently available
• Notes
• There is no min or max function that will
  compare different fields so use this format
• To return minimum value of x or y use iif (x lt
  y,x,y)?
• The min and max functions in XPath only return
  the minimum or maximum value within a field.
• There is no case statement so use nested iif
  statements.
• There is no variable declaration.
• All statements must be included in a single
  statement. You cannot return multiple values.
• The first expression that returns a true in a
  nested iif statement returns the value and ends
  the iif.
• It is like writing if xy then x end if, if
  yz then z end if

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12. Examples

• For a simple price list
• 1-10 _at_ 1.75
• 11-25 _at_ 1.50
• 26 and over _at_ 1.25
• ((iif (../_at_quantityOrdered lt 10,
  (../_at_quantityOrdered 1.75,
• iif (../_at_quantityOrdered gt 11 and
  ../_at_quantityOrdered lt 25, (../_at_quantityOrdered
  1.50, (../_at_quantityOrdered 1.25))))?

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12. Examples

• Final Size in 8.5 x 11 equivalents
• ((../../_at_finalSizeHeight div (../../../../_at_sizeDen
  ominator))
• (../../_at_finalSizeWidth div (../../../../_at_sizeDen
  ominator))?
• 93.5)?

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12. Examples

• Banner Hemming - result is final size
• perimeter feet
• (((../../_at_finalSizeHeight div
• (../../../../_at_sizeDenominator 12))
  (../../_at_finalSizeWidth div
• (../../../../_at_sizeDenominator 12))) 2
  ../_at_quantityOrdered

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12. Examples

• Grommets - for each part, put a grommet along
  each side. Max span 4 feet, minimum 4 per piece
  (each corner)?
• ../_at_quantityOrdered (ceiling((../../_at_finalSizeHe
  ight div (../../../../_at_sizeDenominator 12)) div
  4 ) 2
• ceiling((../../_at_finalSizeWidth div
  (../../../../_at_sizeDenominator 12)) div 4 ) 2)?

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12. Examples

• Laminating - 28" wide - run inches. If the sheet
  width is over 28" it has to run short edge into
  the laminator, if under 28" then long edge.
• (iif((../EstimatePress_at_pressIndicator0/_at_runSize
  Width div (../../../../_at_sizeDenominator)gt28,
• ((../EstimatePress_at_pressIndicator0/_at_runSizeWidt
  h div (../../../../_at_sizeDenominator)),
• ((../EstimatePress_at_pressIndicator0/_at_runSizeHeig
  ht div (../../../../_at_sizeDenominator))?
• )) ../_at_sheetsOffPress

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12. Examples

• Laminating - 28" wide - run inches - add 20 if
  under 7 point or over 16 point or quantity is
  under 1000. If the sheet width is over 28" it has
  to run short edge into the laminator, if under
  28" then long edge.
• iif(../EstimatePaper1/paperWeight/_at_caliper lt
  .007,1.2,
• iif(../EstimatePaper1/paperWeight/_at_caliper gt
  .016,1.2,
• iif(../_at_sheetsOffPress lt 1000,1.2,1)))
• (iif((../EstimatePress_at_pressIndicator0/_at_runSize
  Width div (../../../../_at_sizeDenominator)gt28,
• ((../EstimatePress_at_pressIndicator0/_at_runSizeWidt
  h div (../../../../_at_sizeDenominator)),
• ((../EstimatePress_at_pressIndicator0/_at_runSizeHeig
  ht div (../../../../_at_sizeDenominator))?
• )) ../_at_sheetsOffPress

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12. Examples

• Laminate material per side in MSI
• (../EstimatePress_at_pressIndicator0/_at_runSizeWidth
  div ../../../../_at_sizeDenominator)
• (../EstimatePress_at_pressIndicator0/_at_runSizeHeigh
  t div ../../../../_at_sizeDenominator)?
• ../_at_sheetsOffPress div 1000

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12. Examples

• To apply a calculation to the first part of an
  estimate
• iif(../../_at_id min(../../../EstimatePart/_at_id),ltva
  lue or expressiongt,0)?
• For the Preflight Operation this would be
• iif(../../_at_id min(../../../EstimatePart/_at_id),
• (.25 (sum(../../../EstimatePart/_at_totalPages)
  div 600)) 100,0)?

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12. Examples

• To get the total material cost for an Estimate
  Part, from a prepressOp or finishingOp for
  Canadian tax
• This shows 2 conditions, EstimateActivity.estimate
  Quantity (../_at_id) AND EstimateActivity.hours
  0
• Return 12 of the total material cost on the part
• 0.12 sum(../EstimateActivity_at_estimateQuantity(
  ../_at_id) and null-to-zero(_at_hours) 0/_at_cost)?

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• Thank you for attending