The BOM Procedure

STRUCTURE Statement

STRUCTURE / options;

The STRUCTURE statement lists the variables in the Product Structure and the Part Master input data sets. The main variable in the Part Master data set is the Part variable; the main variables in the Product Structure data set are the Parent and Component variables. If all the part master data are contained in the Product Structure data set, you need not specify a Part Master data set.

If two separate input data sets are specified, you must specify both a Part variable and a Parent variable. Otherwise, you may specify either a Parent variable or a Part variable, or both. You must always specify at least one Component variable. The number of Component variables specified must be equal to the number of the product structure records (number of relationships specified) in each observation of the Product Structure data set. All other variables are optional. However, if you specify the Quantity , Offset , or Factor variables, you must have the same number of these variables as the number of Component variables.

In this statement, you can also explicitly specify the items that are to be used as the end (level-0) items.

COMPONENT=variables COMP=variables

specifies variables in the Product Structure input data set that contain the part numbers (identifications) of the components that are directly used in the common parent item identified by the Parent variable. These variables are also referred to as Component variables. The Component variables must be of the same type, format, and length as the Part variable in the Part Master data set. At least one Component variable must be specified.

Note: This variable is case-sensitive when it is in character format.

ENDITEM=enditems

specifies the items that are to be used as the highest level or level-0 items (also referred to as end items) in the indented bill of material. In other words, this option can be used to construct indented bill of material and summarized parts list for sub-assemblies. The values for enditems must be either numbers (if the Part variable is numeric) or quoted strings (if the Part variable is character). If you do not specify this option, the procedure assumes every final product (finished good) is an end item and builds an indented bill of material for it.

FACTOR=variables SFACTOR=variables

identifies variables in the Product Structure data set that contain the scrap factor information for each product structure record with the parent item identified by the Parent variable and the component identified by each of the Component variables; the ith factor variable corresponds to the ith Component variable. The scrap factor is used to increase the gross requirement to account for anticipated loss within the manufacture of a particular parent item (Cox and Blackstone 1998). These variables are also referred to as the Factor variables. The variables specified must be numeric and the number of Factor variables must be equal to the number of Component variables. If you do not specify this option, PROC BOM assumes the scrap factors for all product structure records to be 0.

ID=variables

identifies all variables in the Part Master data set that are not specified in the LEADTIME= , PART= , QTYONHAND= , or REQUIREMENT= options, and are to be included in the Indented BOM and the Summarized Parts output data sets. These variables are also referred to as ID variables. An ID variable cannot be named as: Gros_Req, _Level_, L_Offset, Low_Code, Net_Req, On_Hand, _Parent_, Paren_ID, _Part_, Part_ID, _Prod_, Qty_Per, Qty_Prod, S_Factor, Tot_Lead, or Tot_Off. This option is useful for carrying any identifying and descriptive information (part description, unit of measure, etc.) and control values (lot size, unit cost, etc.) about each item (identified by the Part variable) from the Part Master data set to the output data sets.

LEADTIME=variable DUR=variable

identifies the variable in the Part Master data set that contains the lead time information for the item identified by the Part variable. The lead time of an item is the length of time between recognition of the need for an order and the receipt of the goods. Individual components of lead time can include order preparation time, queue time, processing time, move or transportation time, and receiving and inspection time (Cox and Blackstone 1998). This variable is also referred to as the LeadTime variable. The variable specified must be numeric. If you do not specify this option, PROC BOM assumes the lead time for each item to be 0. On the other hand, if this option is specified, the procedure creates a new variable, Tot_Lead, in the Indented BOM data set to contain the total lead time. See the section Indented BOM Data Set for details about the calculation of the total lead time.

OFFSET=variables LTOFFSET=variables

identifies variables in the Product Structure data set that contain the lead-time offset information for each product structure record with the parent item identified by the Parent variable and the component identified by each of the Component variables; the ith offset variable corresponds to the ith Component variable. The lead-time offset can be used to control when materials are issued to a work center as well as to determine the need date when planning, purchasing, or manufacturing a particular component (Clement, Coldrick, and Sari 1992). These variables are also referred to as the Offset variables. The variables specified must be numeric and the number of Offset variables must be equal to the number of Component variables. If you do not specify this option, PROC BOM assumes the lead-time offsets for all product structure records to be 0. On the other hand, if this option is specified, the procedure creates a variable, Tot_Off, in the Indented BOM data set to contain the total offset. See the section Indented BOM Data Set for details about the calculation of the total offset.

Note: The lead-time offset and the total offset can be expressed in units that are different from the lead time.

PARENT=variable

specifies the variable in the Product Structure data set that contains the part number or identification for the immediate parent item of the components identified by the Component variables. This variable is also referred to as the Parent variable. The Parent variable must be of the same type, format, and length as the Part variable in the Part Master data set. You must specify this option whenever a Part Master data set is explicitly specified in addition to the Product Structure data set. On the other hand, if a Part Master data set is not specified, the Parent variable is not necessary; if this variable is not specified, the procedure assumes that it is the same as the variable specified in the PART= option.

Note: This variable is case-sensitive when it is in character format.

PART=variable ITEM=variable

specifies the variable in the Part Master data set that contains the part number or identification. This variable is also referred to as the Part variable. The Part variable can be either character or numeric. You must specify this option whenever a Part Master data set is specified in addition to the Product Structure data set. Otherwise, the Part variable is not necessary; if this variable is not specified, the procedure assumes that it is the same as the variable specified in the PARENT= option.

Note: This variable is case-sensitive when it is in character format.

QTYONHAND=variable INVENTORY=variable

identifies the variable in the Part Master data set that contains the quantity currently on hand for the item identified by the Part variable. This variable is also referred to as the QtyOnHand variable. The QtyOnHand variable must be numeric. If you do not specify the QtyOnHand variable, the procedure assumes that you do not have any items on hand.

QUANTITY=variables QTYPER=variables

identifies variables in the Product Structure data set that contain the quantity per assembly information for each product structure record with the parent item identified by the Parent variable and the components identified by each of the Component variables; the ith quantity variable corresponds to the ith Component variable. The quantity per assembly for a given parent-component relationship is the quantity of the component to be used in the production of 1 unit of the parent item. These variables are also referred to as the Quantity or QtyPer variables. The variables specified must be numeric and the number of Quantity variables must be equal to the number of Component variables. If you do not specify these variables, the procedure assumes that you need 1 unit of each listed component identified by a Component variable to make 1 unit of the parent item identified by the Parent variable.

REQUIREMENT=variable GROSSREQ=variable

identifies the variable in the Part Master data set that contains the gross requirement (the quantity planned to be produced in a production plan) for the item identified by the Part variable. This variable is also referred to as the Requirement variable and must be numeric. If you do not specify this option, the procedure assumes that the gross requirements for all items are missing except for the final products or end items. All final products or end items are assumed to have gross requirements of 1 unit. In other words, if the Part Master data set does not contain the production plan information, PROC BOM uses a default production plan in which each end item has a requirement of 1 unit. The procedure uses the specified (or assumed) values of the Requirement variable to calculate the gross requirements for all other items. These values are saved in the Requirement variable in the Summarized Parts output data set if the SUMMARYOUT= option is specified. If the REQUIREMENT= option is not specified, the Summarized Parts data set uses the default name, Gros_Req.

See the section Summarized Parts Data Set for details on the calculation of the gross requirements.

RID=variable

identifies all variables in the Product Structure data set that are not specified in the COMPONENT= , FACTOR= , OFFSET= , PARENT= , or QUANTITY= options, and are to be included in the Indented BOM data set. These variables are also referred to as RID variables. The RID variables cannot be named as: _Level_, L_Offset, _Parent_, Paren_ID, _Part_, Part_ID, _Prod_, Qty_Per, Qty_Prod, S_Factor, Tot_Lead, or Tot_Off. This option is useful for carrying other information stored in a product structure record to the Indented BOM data set. This typically includes engineering effectivity, operation number, reference designator, and line sequence number.

The number of RID variables specified must be a multiple of the number of the Component variables. If you specify m RID and n Component variables as

   component=(COMP1-COMPn)
   RID=(VAR1-VARm)

the procedure distributes these m RID variables to each product structure record with the parent item identified by the Parent variable and the component identified by each of the Component variables in the following manner:

component	1st RID variable	2nd RID variable	…	kth RID variable
`COMP` $_1$	`VAR` $_1$	`VAR` $_{n+1}$		`VAR` $_{m-n+1}$
`COMP` $_2$	`VAR` $_2$	`VAR` $_{n+2}$		`VAR` $_{m-n+2}$
..…
`COMP` $_ n$	`VAR` $_ n$	`VAR` $_{2n}$		`VAR` $_ m$

where $k=m/n$ . Note that the procedure treats the variables VAR $_1$ to VAR $_ n$ as the first RID variable for each of the n product structure records, and hence, they must have the same type, format, and length. The same rules apply to variables VAR $_{n+1}$ to VAR $_{2n}$ , …, VAR $_{m-n+1}$ to VAR $_ m$ , etc.