Fuzzy Duplicates Analysis with ACL Prepared by: Kevin Legere Date: April 3 rd , 2013

Fuzzy Duplicates Analysis with ACL

Prepared by: Kevin Legere

Date: April 3rd, 2013

2© 2012 ACL Services Ltd.ACL | Transforming Audit and Risk

Agenda Overview

Example

FUZZYDUP command

OMIT() Function

Script Editor and RECOFFSET

Q&A


Overview What is a "Fuzzy Duplicate"?

– Match based on criteria where the values are not exact but very close» EX: "ACL Services" and "ACL Service"

Typically used for:» Keyword matching» Invoice Number matching» Vendor Name matching*» Employee Name matching

Can be simple or complex» Completely depends on your approach and desired accuracy

* focus for this presentation


Overview Simple Match Examples:

– Exact or 100% match» "ACL" = "ACL"

– Force Upper or Lower case» "ACL" = UPPER("acl")» "acl" = LOWER("ACL")

– Removal of special characters» "ACL" = EXCLUDE("*ACL." "!@#$%^&*().")

– Only compare numbers or letters» "ACL" = INCLUDE(UPPER("ACL123") "ABCDEFGHIJKLMNOPQRSTUVWXYZ")» "123" = INCLUDE("ACL123" "1234567890")


Overview Complex Match Examples:

– Removal of company type indicators (LLC, INC, LTD, etc) » "ACL Services Ltd." = "ACL Services"

– Percent of word match AKA letter by letter» "ACL Services" "ACL Service"

• 11/12 character match or 91.6% match– Word by Word*

» "ACL Services" "ACL Champions"• "ACL" "ACL" • "Services" "Champions"• = 50% match

– Levenshtein distance– Sounds like– NYSIIS

*Most used by ACL Consultants


Vendor Master Analysis


Fuzzy Duplicates on Vendor Name– Possible Risk

» Payments are being sent to more than one vendor

– May not involve risk. The desire can be to normalize the vendor master list to ensure that duplicates do not exist.

» Ideally, one unique vendor should exist in your vendor master list with one or more address records in your vendor address table



Sample file contains 75 vendors– Only Vendor Code and Vendor Name

Where do you start for Vendor Name matching?– Look for exact duplicates– Focus on Simple matching– Sort or Summarize!


Sample Vendor Master


Step 1: Summarize your Vendor Master File » Choose Vendor Name as your key field» Add Vendor Code as the Other Fields for Summarizing » Be sure to check "Presort"



Step 2: Quickly comb over the data to identify a common trend. » We will focus on this issue, in the sample data:

» Create a computed field that corrects the trend (or cleans the data).



Functions used in Default Value text box:

INCLUDE(UPPER(ALLTRIM(Vendor_Name)) 'ABCDEFGHIJKLMNOPQRSTUVWXYZ')

Within ACL, the computed field will return the following:



Step 3: Perform a Duplicates Command on the computed field



Results are as follows:



ACL 9.3 has new features that make Fuzzy Duplicate analysis easier– FUZZYDUP command– OMIT() function– ISFUZZYDUP() function– LEVDIST() function

Important parameters to understand– Levenshtein Distance – Difference Percentage

FUZZYDUP command


Syntax– FUZZYDUP ON {key_field} <OTHER fields> {LEVDISTANCE value} <DIFFPCT value><RESULTSIZE

value> <EXACT> TO table_name

Example– FUZZYDUP ON Vendor_Name OTHER ALL LEVDISTANCE 2 DIFFPCT 50 TO My_Results

Levenshtein Distance (LEVDISTANCE)

» The number of edits required to make the strings equal• EX: "Smith" and "Smythe" have a Levenshtein Distance of 2

Difference Percentage (DIFFPCT)

» The threshold for percentage difference between two strings• EX: "Smith" and "Smythe" have a Percentage Difference of 40% • (2/5) * 100%

FUZZYDUP command


When Do I use OMIT()?– When you want to refine fuzzy duplicate analysis– Look for repeating strings you want to remove from your Vendor Name field

Syntax– OMIT(string1, string2 <,case_sensitive>)– Specify T to make substrings specified for removal case-sensitive, or F to ignore

case

Example– OMIT(Vendor_Name " Ltd, Inc, Corp, Corporation" F)

OMIT() Function


Script Editor and RECOFFSET



Contact Information

Kevin LegereImplementation

Consultant

ACL Services Ltd.1550 Alberni Street, Vancouver, BC, Canada V6G 1A5 [email protected] | @aclkevinwww.acl.com/linkedin | www.acl.com/twitter | www.acl.com/facebook

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Fuzzy Duplicates Analysis with ACL Prepared by: Kevin Legere Date: April 3 rd , 2013