Cost Model Overview

The aPriori Wire Harness Process Group provides the ability to automatically cost wire harnesses of moderate complexity .

To do this, aPriori requires three simple inputs:

  • Outputs from your Wire Harness design tool in a standardized, .csv format.

  • A component type identifier for each part number, such as "Termination", "Wire", "Connector", etc.

  • Standard prices for purchased components, wires, braids, etc. This is typically in the form of a Component Library that is set up by an aPriori administrator, mapping Customer Part Numbers and Manufacturer Part Numbers.

If you are an engineer designing a Wire Harness, you can generate your drawings and then generate .csv output tables to check your costs immediately, allowing you to make design decisions now rather than weeks later when receiving supplier quotes.

If you work in purchasing, you can analyze your Wire Harness costs at a component level, and start to negotiate from a more knowledgeable position with your suppliers.

Note: The separately-licensed Wire Harness Process Group is somewhat different than other aPriori process groups: it is implemented as a Digital Factory that your administrator(s) import and configure for the users at your site. This Digital Factory Factory consists of two process groups that have been customized for Wire Harness costing: Assembly, and User Guided. aPriori also provides a "transformation utility" for converting the output from your Wire Harness design system into a consistent format that can be read by aPriori. You do not really need to be concerned with these architectural details, since aPriori configures the Wire Harness cost model specifically for your company, and provides an easy-to-use interface to walk you through the costing process.

Wire harnesses are considered a type of assembly, but geometric cost drivers (GCDs) are not available the same way they would be for CAD model-based components. Cost drivers are provided via attributes from standard Wire Harness definition tables

Instead of depending on CAD model GCDs, aPriori extracts cost driver information from standard tables generated by the Wire Harness design tools, typically in the form of .csv files. Users augment the information from these imported files with user-guided data, and with component library information.  Most components will be off-the-shelf parts, but we know that many companies specify internal part numbers rather than manufacturer or distributor part numbers. To associate information from the tables to the purchased component information, aPriori Professional Services first maps your internal part numbers to manufacturer or distributor part numbers in a Component Library in the Digital Factory.

This chapter covers day-to-day costing operations and assumes that aPriori Professional Services has worked with your Administrators to set up and configure this cost model, including the Component Library. See the aPriori System Administration Guide and Digital Factory Administration Guide for more information about configuration and maintenance of the Wire Harness and PCBA environments.

aPriori does not make any assumptions about which specific Wire Harness design tool is being used: it could range from a standard CAD tool such as PTC Pro/ENGINEER, to a dedicated Wire Harness tool such as Zuken E3.series, to a drawing tool such as AutoCAD.  The one assumption that we do make is that each of these tools can output most of the inputs that aPriori requires, into a consistent .csv table format. aPriori takes these tables and processes them through a data transformation tool which creates a spreadsheet that can be read by the aPriori BOM loader for the Wire Harness process group.

General Process

Wire harnesses are assemblies that consist of mostly purchased components with minimal processing required. These components can include:

  • Wires, which are purchased in bulk lengths and cut and stripped as needed on a component by component basis (wire by wire basis). These can include -- but are not limited to -- the examples shown below:

  • Dressing materials and labels, such as tape, bundling materials, insulation, etc., which are purchased and processed in a similar fashion. Examples of dressing materials can include:

  • Connectors, pins, terminals, seals, and everything that goes on the ends of a Wire Harness. These components are typically purchased as-is and just assembled. A few connector examples include:

For a Wire Harness with normal complexity, aPriori costs the following steps:

  • Preparation of the wires and cables. This step includes cutting the wires or cables to length. Also, some additional operations may be carried out such as marking, sealing, molding, sleeving, or labeling of the wires or connectors. 

  • Assembly of the harness on a board or jig. This includes manually laying-in the wires and cables, inserting the wire ends into connectors if necessary, tying, or taping the bundles or wires and/or sleeving the bundles. Testing is usually done at this stage and some labeling may also be carried out.

Note: aPriori does not currently cost installation of the interconnections or the cable harness into the chassis or product.

Component Types

aPriori recognizes the following Wire Harness component types and subtypes:

 

Description

Type

Subtype

Sub-Subtype

Wire

W

W1 -- Single Conductor Stranded Insulated WireW2 -- Single Conductor Solid Insulated WireW3 -- Multi-Conductor CableW4 -- Coax CableW5 -- Triax CableW6 -- Ribbon CableW7 -- Solid Buss

 

Terminations

T

T1 -- ContactsT2 -- Ring/Fork/Blade TerminalsT3 -- Tinned WiresT4 -- Shield TerminatorsT5 -- Wire Ferrules

T1A CrimpedT1B SolderedT2A Crimped    T2AA Machine Crimped    T2AM Manually CrimpedT2B SolderedT4A CrimpedT4B SolderedT5A Machine CrimpedT5M Manually Crimped

Connectors

C

C1 -- Unloaded Connectors (default)C2 -- Loaded ConnectorsC3 -- Ribbon Cable ConnectorsC4 -- Coax ConnectorsC5 -- Triax ConnectorsC6 -- Wedge LocksC7 -- BackshellsC8 -- Strain ReliefsC9 -- Dust CapsC10 -- Shrink Boots

 

Splices

P

P1 -- Ultrasonic WeldsP2 -- Butt SplicesP3 -- Insulation Displacement Splices

 

Dressing

D

D1 -- Cable TiesD2 -- Seal TapeD3 -- BraidD4 -- Heat Shrink TubingD5 -- Single Braided SleevingD6 -- Double Braided SleevingD7 -- Expando Braided SleevingD8 -- Split Loom TubingD9 -- Plain Flexible ConduitD10 -- Liquid Tight ConduitD11 -- Spiral WrapD12 -- EMI Braiding

 

Labels

L

L1 -- Heat Shrink LabelsL2 -- Wrap-Around Labels

 

Seals

S

S1 -- PlugsS2 -- Wire Seals

 

Bundles

B

 

 

Twists

TW

 

 

Routings

The User Guided Process Group for Wire Harness consists of the following routings based on the above component types:

  • Wire Prep (Component Cost, Cut, Strip) - For type Wire (W).

  • Dressing Prep (Component Cost, Cut) - For type Dressing (D), either individual or applied to Bundles or Splices.

  • No Prep (Component Cost only) - For all remaining types.

The Assembly Process Group routing for Wire Harness are summarized in the following illustration:

Cost Driver Extraction

Your Wire Harness design tool must output some or all of the following tables in .csv format. aPriori extracts cost driver information about a Wire Harness from these tables, which serve as input to the aPriori Transformation Utility (see the next section).

Table Name

Comments

Contains

BOM

Required.

(Should not be confused with the BOM generated by the transformation utility for the aPriori BOM loader.)

An itemized list and quantity for each component that appears in the Wire Harness. Required columns are:
Part Number (internal)
Quantity

Wire Table (aka Circuit Data Table, Wire Cut List)

Optional

Information about all of the wires in the Wire Harness including:

  • Wire ID number (reference to schematic)

  • Length

  • Gauge

  • Color

BUNDLE

Optional

Provides cost granularity

Information about all of the bundles in the Wire Harness, such as:

  • Bundle ID number (reference to schematic)

  • Bundle diameter

  • Bundle length

  • Dressing material part number

SPLICE

Optional

Provides cost granularity

Information about all of the splices in the Wire Harness, such as:

  • Splice ID Number (reference to schematic)

  • Involved wire information

  • Insulation part number

  • Insulation length

TWIST

Optional

Provides cost granularity

Information about all of the twists in the Wire Harness, such as:

  • Twist ID number (reference to schematic)

  • Involved wire IDs

The information from the tables above contain almost all of the information that aPriori needs to develop a complete cost.