managing the business risk of fraud

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Managing the business risk of fraud using sampling and data mining EZ-R Stats, LLC Managing the Business Risk of Fraud using Sampling and Data Mining Fall 2009 Mike Blakley Mike Blakley Presented to:

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Managing the business risk of fraud using sampling and data mining

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  • 1. Managing the Business Risk of Fraud using Sampling and Data Mining Fall 2009 Mike Blakley Presented to:

2. PWC Global Survey Nov, 2009 Economic crime in a downturn

  • Sharp rise in accounting fraud over the past 12 months
  • Accounting fraud had grown to 38 percent of the economic crimes in 2009
  • Employees face increased pressures to :
    • meet performance targets
    • keep their jobs
    • keep access to funding

3. Survey findings

  • Greater risk of fraud due to increased incentives or pressures
  • More opportunitiesto commit fraud, partially due toreductions in internal finance staff
  • While companies are expecting more fraud, theyhave not done much
  • People who look for fraud are more likely to find it

4. Session objectives

  • Understand the framework for managing the business risk of fraud
  • Plan, perform and explain statistical sampling in audits
  • Reduce audit costs using data mining, sequential sampling and other sampling techniques
  • Apply SAS 56, the new SAS suite and the revised (2007) Yellow Book.
  • Run, hands-on, the most productive analytic technique (regression analysis).
  • Use data mining to introduce greater efficiency into the audit process, without losing effectiveness.

5. Session agenda - 1

  • Introduction and the Process for Managing the Business Risk of Fraud
  • Introductions All Around
  • Course Objectives
  • Framework of risk management for fraud
  • Fundamentals of data mining
  • Data mining: The Engine That Drives analysis
    • Analytics and Regression
      • Sources of Analytics Data
      • Basic and Intermediate ARTs
  • SAS 56
  • IIA Practice Advisory 2320
  • The Yellow Book (2007 revision)
  • The Guide Managing the Business Risk of Fraud

6. Session Agenda (contd) Sampling refresher

  • Sampling
  • The sampling process
  • Sampling methods
  • RAT-STATS
    • Random Numbers
    • Determining Sample Size
    • Case Study
    • Attribute sampling
    • Variable Sampling
    • Case study
    • Stratified Sampling
    • Obtaining and Interpreting the results
  • Other Sampling Approaches
  • DCAA Audit Package
  • Sequential Sampling
  • Overview of the process
  • Attribute Sampling
  • Variable Sampling

7. Session Agenda (contd) Linear regression as anaudit tool

  • Regression Analysis
  • Overview
  • Terms
  • Statistical basis
  • Charting Regression Seeing Is Believing
  • Plotting Data
    • Inserting a Trend line
  • Statistical Intervals
    • Confidence Intervals
    • Prediction Intervals
    • Calculation of Statistical Confidence Bounds
  • Case Study - Wake County Schools Bus Maintenance

8. Session Agenda (contd) Data mining, or How to test 100%

  • Overview
  • Statistical Basis
  • Data Conversion and Extraction
  • Data mining objectives
    • Classification
    • Trends
    • Identification of extremes
    • Major types of data analysis
      • Numeric
      • Date
      • Text

9. Session Agenda (contd) Excel as an Analytics tool

  • Macros
  • Tools Data Analysis
  • The Macro facility
    • Adding a little class to your audit
    • VBA friend or foe

10. Handout (CD)

  • CD with articles and software
  • PowerPoint presentation
  • More info at www.ezrstats.com

11. Cockroach theory of auditing

  • If you spot one roach.

12. Cockroach theory of auditing

  • There are probably 30 more that you dont see

13. Statistics based roach hunting Many frauds coulda/woulda/shoulda been detected with analytics 14. Overview

  • Fraud patterns detectable with digital analysis
  • Basis for digital analysis approach
  • Usage examples
  • Continuous monitoring
  • Business analytics

15. The Why and How

  • Three brief examples
  • ACFE/IIA/AICPA Guidance Paper
  • Practice Advisory 2320-1
  • Auditors Top 10
  • Process Overview
  • Who, What, Why, When & Where

Objective 1 16. Example 1 Wake County Transportation Fraud

  • Supplier Kickback School Bus parts
  • $5 million
  • Jail sentences
  • Period of years

Objective 1a 17. Too little too late

  • Understaffed internal audit
  • Software not used
  • Data on multiple platforms
  • Transaction volumes large

Objective 1a 18. Preventable

  • Need structured, objective approach
  • Let the data talk to you
  • Need efficient and effective approach

Objective 1a 19. Regression Analysis

  • Stepwise to find relationships
    • Forwards
    • Backwards
  • Intervals
    • Confidence
    • Prediction

Objective 1 20. Dataoutliers

  • Sometimes an out and outLiar
  • But how do youdetectit?

Objective 1 21. Data Outliers

  • Plot transportation costs vs. number of buses
  • Drill down on costs
    • Preventive maintenance
    • Fuel
    • Inspection

Objective 1 22. Scatter plot with prediction and confidence intervals 23. Cost of six types of AIDS drugs Example 2 Objective 1a 24. Medicare HIV Infusion Costs

  • CMS Report for 2005
  • South Florida -$2.2Billion
  • Rest of the country combined -$.1Billion

Objective 1 25. Pareto Chart Objective 1 26. Typical Prescription Patterns Example 2 Objective 1a 27. Prescriptions by Dr. X Example 2 Objective 1a 28. Off-label use

  • Serostim
    • Treat wasting syndrome, side effect of AIDS,OR
    • Used by body builders for recreational purposes
    • One physician prescribed $11.5 million worth (12% of the entire state)

Example 2 Objective 1a 29. Revenue trends Example 3 Objective 1a 30. Dental Billings Example 3 Objective 1a 31. Guidance Paper

  • A proposed implementation approach
  • Managing the Business Risk of Fraud: A Practical Guidehttp://tinyurl.com/3ldfza
  • Five Principles
  • Fraud Detection
  • Coordinated Investigation Approach

Objective 1b 32. Managing the Business Risk of Fraud: A Practical Guide

  • ACFE,IIA andAICPA Exposure draft issued 11/2007, final 5/2008
  • Section 4 Fraud Detection

Objective 1b 33. Guidance Paper

  • Five Sections
    • Fraud Risk Governance
    • Fraud Risk Assessment
    • Fraud Prevention
    • Fraud Detection
    • Fraud Investigationand corrective action

34. Risk Governance

  • Fraud risk management program
  • Written policy managements expectations regarding managing fraud risk

35. Risk Assessment

  • Periodic review and assessment of potential schemes and events
  • Need to mitigate risk

36. Fraud Prevention

  • Establish prevention techniques
  • Mitigate possible impact on the organization

37. Fraud Detection

  • Establish detection techniques for fraud
  • Back stop where preventive measures fail, or
  • Unmitigated risks are realized

38. Fraud Investigation and Corrective Action

  • Reporting process to solicit input on fraud
  • Coordinated approach to investigation
  • Use of corrective action

39. 60 Minutes World of Trouble

  • 2/15/09 Scott Pelley
    • Fraud Risk Governance one grand wink-wink, nod-nod
    • Fraud Risk Assessment - categorically false
    • Fraud Prevention my husband passed away
    • Fraud Detection -We didn't know? Never saw one.
    • Fraud Investigationand corrective action - Pick-A-Payment losses $36 billion

40. Section 4 Fraud Detection

  • Detective Controls
  • Process Controls
  • Anonymous Reporting
  • Internal Auditing
  • Proactive Fraud Detection

Objective 1b 41. Proactive Fraud Detection

  • Data Analysis to identify:
    • Anomalies
    • Trends
    • Risk indicators

Objective 1b 42. Fraud Detective Controls

  • Operate in the background
  • Not evident in everyday business environment
  • These techniques usually
    • Occur in ordinary course of business
    • Corroboration using external information
    • Automatically communicate deficiencies
    • Use results to enhance other controls

43. Examples of detective controls

  • Whistleblower hot-lines (DHHS and OSA have them)
  • Process controls (Medicaid audits and edits)
  • Proactive fraud detection procedures
    • Data analysis
    • Continuous monitoring
    • Benfords Law

44. Specific Examples Cited

  • Journal entries suspicious transactions
  • Identification of relationships
  • Benfords Law
  • Continuous monitoring

Objective 1b 45. Data Analysis enhances ability to detect fraud

  • Identify hidden relationships
  • Identify suspicious transactions
  • Assess effectiveness of internal controls
  • Monitor fraud threats
  • Analyze millions of transactions

Objective 1b 46. Continuous Monitoring of Fraud Detection

  • Organization should develop ongoing monitoring and measurements
  • Establish measurement criteria (and communicate to Board)
  • Measurable criteria include:

47. Measurable Criteria number of

  • fraud allegations
  • fraud investigations resolved
  • Employees attending annual ethics course
  • Whistle blower allegations
  • Messages supporting ethical behavior delivered by executives
  • Vendors signing ethical behavior standards

48. Management ownership of each technique implemented

  • Each process owner should:
    • Evaluate effectiveness of technique regularly
    • Adjust technique as required
    • Document adjustments
    • Report modifications needed for techniques which become less effective

49. Practice Advisory 2320-1 Analysis and Evaluation

  • International standards for the professional practice of Internal Auditing
  • Analytical audit procedures
    • Efficient and effective
    • Useful in detecting
      • Differences that are not expected
      • Potential errors
      • Potential irregularities

50. Analytical Audit Procedures

  • May include
    • Study of relationships
    • Comparison of amounts with similar information in the organization
    • Comparison of amounts with similar information in the industry

51. Analytical audit procedures

  • Performed using monetary amounts, physical quantities, ratios or percentages
  • Ratio, trend andregression analysis
  • Period to period comparisons
  • Auditors should use analytical audit procedures in planning the engagement

52. Factors to consider

  • Significance of the area being audited
  • Assessment of risk
  • Adequacy of system of internal control
  • Availability and reliability of information
  • Extent to which procedures provide support for engagement results

53. Peeling the Onion Objective 1c Population as Whole Possible Error Conditions Fraud Items 54. Fraud Pattern Detection Objective 1d Market Basket Stratification Trend Line Holiday Day of Week Duplicates Univariate Gaps Benfords Law Round Numbers Target Group 55. Digital Analysis (5W)

  • Who
  • What
  • Why
  • Where
  • When

Objective 1e A little about the basics of digital analysis. 56. Who Uses Digital Analysis

  • Traditionally, IT specialists
  • With appropriate tools, audit generalists (CAATs)
  • Growing trend of business analytics
  • Essential component of continuous monitoring

Objective 1e 57. What - Digital Analysis

  • Using software to:
    • Classify
    • Quantify
    • Compare
  • Both numeric and non-numeric data

Objective 1e 58. How - Assessing fraud risk

  • Basis is quantification
  • Software can do the leg work
  • Statistical measures of difference
    • Chi square
    • Kolmogorov-Smirnov
    • D-statistic
  • Specific approaches

Objective 1e 59. Why - Advantages

  • Automated process
  • Handle large data populations
  • Objective, quantifiable metrics
  • Can be part of continuous monitoring
  • Can produce useful business analytics
  • 100% testing is possible
  • Quantify risk
  • Repeatable process

Objective 1e 60. Why - Disadvantages

  • Costly (time and software costs)
  • Learning curve
  • Requires specialized knowledge

Objective 1e 61. When to Use Digital Analysis

  • Traditional intermittent (one off)
  • Trend is to use it as often as possible
  • Continuous monitoring
  • Scheduled processing

Objective 1e 62. Where Is It Applicable?

  • Any organization with data in digital format, and especially if:
    • Volumes arelarge
    • Data structures arecomplex
    • Potential for fraudexists

Objective 1e 63. Disadvantages of digital analysis

  • Cost
    • Software
    • Training
    • Skills not widely available
  • Time consuming
    • Development costs
    • Testing resources

64. Objective 1 Summarized

  • Three brief examples
  • CFE Guidance Paper
  • Top 10 Metrics
  • Process Overview
  • Who, What, Why, When & Where

Objective 1 65. Objective 1 - Summarized

  • Understand the framework for managing the business risk of fraud
  • Plan, perform and explain statistical sampling in audits
  • Reduce audit costs using data mining, sequential sampling and other sampling techniques
  • Apply SAS 56, the new SAS suite and the revised (2007) Yellow Book.
  • Run, hands-on, the most productive analytic technique (regression analysis).
  • Use data mining to introduce greater efficiency into the audit process, without losing effectiveness.

Next is plan, perform 66. Statistical Sampling

  • Brief History / Timeline
  • Overview
  • Attribute Sampling Compliance
  • Variable Sampling Numeric Estimates

67. History of Sampling

  • Basis is two laws/theorems of probability
  • Law of Large Numbers
  • Central Limit Theorem

68. Law of large numbers 69. Time Line - LLN

  • Indian mathematician Bramagupta 600 AD
  • Italian mathematician Cardon 1500s
  • Statement without proof that empirical statistics improve with more trials

70. Time line LLN (continued)

  • Jacob Bernoulli first to prove in 1713
  • Foundation for central limit theorem

71. Central limit theorem Classic measure Mean of a sufficiently large number of random samples will be approximately normally distributed. 72. The traditional explanation 73. Central Limit Theorem

  • See it in action today
  • Any population
  • Large number of samples
  • Average is normally distributed

74. History of Central Limit Theorem

  • French mathematician Abraham de Moivre
  • 1733 approximate distribution from tossing coin (heads/tails)
  • Ho hum reaction
  • French Mathematician LaPlace expanded it
  • Ho hum reaction

75. History of CLT (contd)

  • Russian mathematician Lyapunov
  • Proof in 1901
  • Same reaction

76. Industrial revolution Manufacturing Engineering Excitement! 77. Students T William Gosset - 1908 Guinness Brewery 78. SAS 39

  • Effective June, 1983
  • Exposure draft for revision in 2009

79. Attribute sampling

  • Buonaccorsi (1987)
  • Refined calculations
  • Few software packages use it

80. Overview

  • Sample size calculations
  • Attribute sampling
  • Variable sampling
  • Random number generators

81. Sample size calculation

  • Its a guess
  • Every package different answer
  • Need to know the population
  • But thats why youre taking a sample!

82. Attribute Sampling Using RAT-STATS Unrestricted populations 83. Session Objectives

  • Understand what is attribute sampling and when to use it
  • Understand unrestricted populations
  • Overview of the process using RAT-STATS
  • Understand the formula behind the computations

84. Attribute sampling

  • Attribute
  • Compliance testing
  • Signatures on approval documents, attachment of supporting documentation, etc.

85. Statistical approach

  • Recommended
  • Economical
  • Efficient
  • Requires determination of a sample size

86. Overview of process

  • Determine the sampling objective
    • Confidence
    • Precision
  • Determine required sample size
  • Identify samples to be selected based upon random numbers
  • Pull the sample and test
  • Compute the sampling results (i.e. estimate of range)

87. How this is done in RAT-STATS

  • The sampling parameters are first developed by the auditor
  • RAT-STATS is used to compute sample size
  • RAT-STATS used to generate random numbers
  • Pull the sample and test
  • Enter results in RAT-STATS to compute estimates

88. Step 1 Develop sampling parameters

  • Size of population
  • Expected error rate
  • Required confidence
  • Required precision

89. Step 2 Obtain the random numbers

  • Done by entering info into RAT-STATS
  • Output can be a variety of sources:
    • Text File
    • Excel
    • Microsoft Access
    • Print File

90. Step 3 Pull the sample

  • Each random number selected corresponds with an item
  • Put the selected item on a separate schedule

91. Step 4 - Test each selected item

  • Generally requires reviewing documents

92. Step 5 Compute the results

  • Enter summary information into RAT-STATS
  • Output can be in a variety of formats:
    • Excel
    • Microsoft Access
    • Text File
    • Print File
    • Printer

93. Thats It!

  • Now well see an actual demo using the RAT-STATS software
  • Excel population of 5,000 invoices
  • Results of test of attributes stored in the worksheet

94. Variable Sampling Using RAT-STATS Unrestricted populations 95. Session Objectives

  • Understand what variable sampling is and when to use it
  • Understand unrestricted populations
  • Overview of the process using RAT-STATS
  • Understand the formula behind the computations

96. Variable sampling

  • Variable
  • Estimating account balances
  • Estimating transaction totals

97. Statistical approach

  • Recommended
  • Economical
  • Efficient
  • Requires determination of a sample size

98. Overview of process

  • Determine the sampling objective
    • Confidence
    • Precision
  • Determine required sample size
  • Identify samples to be selected based upon random numbers
  • Pull the sample and test
  • Compute the sampling results (i.e. estimate of range)

99. How this is done in RAT-STATS

  • The sampling parameters are first developed by the auditor
  • RAT-STATS is used to compute sample size
  • RAT-STATS used to generate random numbers
  • Pull the sample and test
  • Enter results in RAT-STATS to compute estimates

100. Step 1 Develop sampling parameters

  • Probe sample
  • Statistical measure
  • Excel formula

101. Step 1 Develop sampling parameters

  • Size of population
  • Average value
  • Standard deviation

102. Step 2 Obtain the random numbers

  • Done by entering info into RAT-STATS
  • Output can be a variety of sources:
    • Text File
    • Excel
    • Microsoft Access
    • Print File

103. Step 3 Pull the sample

  • Each random number selected corresponds with an item
  • Put the selected item on a separate schedule

104. Step 4 - Test each selected item

  • Generally requires reviewing documents
  • Example data contains both examined and audited value.

105. Step 5 Compute the results

  • Enter summary information into RAT-STATS
  • Output can be in a variety of formats:
    • Excel
    • Microsoft Access
    • Text File
    • Print File
    • Printer

106. Thats It!

  • Now well see an actual demo using the RAT-STATS software
  • Excel population of 5,000 invoices
  • Audited values stored in the worksheet

107. Attribute Sampling Using RAT-STATS Stratified populations 108. Session Objectives

  • Understand what is stratification and when to use it
  • Overview of the process using RAT-STATS

109. Stratified sampling

  • Strata
  • Homogenous
  • More efficient in some instances

110. Overview of process

  • Separation into strata
  • Determine the sampling objective
    • Confidence
    • Precision
  • Determine required sample size
  • Identify samples to be selected based upon random numbers
  • Pull the sample and test
  • Compute the sampling results (i.e. estimate of range)

111. How this is done in RAT-STATS

  • The sampling parameters are first developed by the auditor
  • RAT-STATS is used to compute sample size
  • RAT-STATS used to generate random numbers
  • Pull the sample and test
  • Enter results in RAT-STATS to compute estimates

112. Step 1 Develop sampling parameters

  • Size of population
  • Expected error rate
  • Required confidence
  • Required precision

113. Step 2 Obtain the random numbers

  • Done by entering info into RAT-STATS
  • Output can be a variety of sources:
    • Text File
    • Excel
    • Microsoft Access
    • Print File

114. Step 3 Pull the sample

  • Each random number selected corresponds with an item
  • Put the selected item on a separate schedule

115. Step 4 - Test each selected item

  • Generally requires reviewing documents

116. Step 5 Compute the results

  • Enter summary information into RAT-STATS
  • Output can be in a variety of formats:
    • Excel
    • Microsoft Access
    • Text File
    • Print File
    • Printer

117. Thats It!

  • Now well see an actual demo using the RAT-STATS software
  • Excel population of 5,000 invoices
  • Results of test of attributes stored in the worksheet

118. Variable Sampling Using RAT-STATS Stratified populations 119. Session Objectives

  • Understand what stratified sampling is and when to use it
  • Populations benefiting from stratified sampling
  • Overview of the process using RAT-STATS
  • Understand the formula behind the computations

120. Stratified variable sampling

  • Stratified
  • Variable
  • Estimating amounts
  • Narrower standard deviation

121. Overview of process

  • Determine the sampling objective
    • Confidence
    • Precision
  • Determine required sample size
  • Identify samples to be selected based upon random numbers
  • Pull the sample and test
  • Compute the sampling results (i.e. estimate of range)

122. How this is done in RAT-STATS

  • The sampling parameters are first developed by the auditor
  • RAT-STATS is used to compute sample size
  • RAT-STATS used to generate random numbers
  • Pull the sample and test
  • Enter results in RAT-STATS to compute estimates

123. Step 1 Develop sampling parameters

  • Probe sample
  • Statistical measure
  • Excel formula

124. Step 1 Develop sampling parameters

  • Number of strata
  • Size of population
  • Average value
  • Standard deviation

125. Step 2 Obtain the random numbers

  • Done by entering info into RAT-STATS
  • Multi-stage random numbers
  • Output can be a variety of sources:
    • Text File
    • Excel
    • Microsoft Access
    • Print File

126. Step 3 Pull the sample

  • Each random number selected corresponds with an item in a strata
  • Put the selected item on a separate schedule

127. Step 4 - Test each selected item

  • Generally requires reviewing documents
  • Example data contains both examined and audited value.

128. Step 5 Compute the results

  • Enter summary information into RAT-STATS
  • Output can be in a variety of formats:
    • Excel
    • Microsoft Access
    • Text File
    • Print File
    • Printer

129. Thats It!

  • Now well see an actual demo using the RAT-STATS software
  • Excel population of 5,000 invoices
  • Divided into three strata
  • Audited values stored in the worksheet

130. Objective 2 - Summarized

  • Understand the framework for managing the business risk of fraud
  • Plan, perform and explain statistical sampling in audits
  • Reduce audit costs using data mining, sequential sampling and other sampling techniques
  • Apply SAS 56, the new SAS suite and the revised (2007) Yellow Book.
  • Run, hands-on, the most productive analytic technique (regression analysis).
  • Use data mining to introduce greater efficiency into the audit process, without losing effectiveness.

Next is cost reduction 131. Techniques for cost reduction

  • Optimize sample size (most bang for the buck)
  • Skip sampling review 100% of transactions usingc omputera ssisteda uditt echniques (CAATs)

132. Sample optimization

  • Sequential sampling

133. University of Hawaii

  • Banana aphids

134. Sequential sampling

  • Banana aphids

135. 100% test using CAATs

  • Provides complete coverage
  • Best practice
  • Basis for continuous monitoring
  • Repeatable process

136. Objective 3 - Summarized

  • Understand the framework for managing the business risk of fraud
  • Plan, perform and explain statistical sampling in audits
  • Reduce audit costs using data mining, sequential sampling and other sampling techniques
  • Apply SAS 56, the new SAS suite and the revised (2007) Yellow Book.
  • Run, hands-on, the most productive analytic technique (regression analysis).
  • Use data mining to introduce greater efficiency into the audit process, without losing effectiveness.

Next is Yellow Book and SAS 56 137. Yellow book standards Standards regarding statistical sampling and IT 138. General standards

  • 3.43 Technical Knowledge and competence
  • The staff assigned to conduct an audit or attestation engagement under GAGAS must collectively possess the technical knowledge, skills, and experience necessary to be competent for the type of work being performed before beginning work on that assignment.
  • The staff assigned to a GAGAS audit or attestation
  • engagement should collectively possess:

139. Stat sampling and IT

  • Skills appropriate for the work being performed. For example, staff or specialist skills in
  • (1)statistical sampling if the work involves use of statistical sampling;
  • (2)information technology

140. SAS 56 Analytical procedures

  • Requiresuse of analytic review procedures for:
  • Audit planning
  • Overall review stages

141. SAS 56 Analytical Review

  • Encouragesuse of analytical review
  • Provides guidance

A wide variety of analytical procedures may be useful for this purpose. 142. Objective 4 - Summarized

  • Understand the framework for managing the business risk of fraud
  • Plan, perform and explain statistical sampling in audits
  • Reduce audit costs using data mining, sequential sampling and other sampling techniques
  • Apply SAS 56, the new SAS suite and the revised (2007) Yellow Book.
  • Run, hands-on, the most productive analytic technique (regression analysis).
  • Use data mining to introduce greater efficiency into the audit process, without losing effectiveness.

Next is linear regression 143. Next Metric

  • Outliers
  • Stratification
  • Day of Week
  • Round Numbers
  • Made Up Numbers
  • Market basket
  • Trends
  • Gaps
  • Duplicates
  • Dates

144. Trend Busters Does the pattern make sense? 7 - Trends 145. Trend Busters

  • Linear regression
  • Sales areup , but cost of goods sold isdown
  • Spikes

7 Trends 146. Purpose / Type of Errors

  • Identify trend lines, slopes, etc.
  • Correlate trends
  • Identify anomalies
  • Key punch errors where amount is order of magnitude

7 Trends 147. Linear Regression

  • Test relationships (e.g. invoice amount and sales tax)
  • Perform multi-variable analysis

7 Trends 148. How is it done?

  • Estimate linear trends using best fit
  • Measure variability (standard errors)
  • Measure slope
  • Sort descending by slope, variability, etc.

7 Trends 149. Trend Lines by Account - Example Results Generally the trend is gently sloping up, but two accounts (43870 and 54630) aredifferent .7 Trends 1.89 -0.560 56 54630 2.36 0.340 23 43870 0.36 1.010 32 43517 0.85 1.023 27 32451 4.3 1.070 17 43517 0.87 1.230 18 32451 Std Err Slope N Account 150. Scatter plot with prediction and confidence intervals 151. Objective 5 - Summarized

  • Understand the framework for managing the business risk of fraud
  • Plan, perform and explain statistical sampling in audits
  • Reduce audit costs using data mining, sequential sampling and other sampling techniques
  • Apply SAS 56, the new SAS suite and the revised (2007) Yellow Book.
  • Run, hands-on, the most productive analytic technique (regression analysis).
  • Use data mining to introduce greater efficiency into the audit process, without losing effectiveness.

Next is data mining 152. Basis for Pattern Detection

  • Analytical review
  • Isolate the significant few
  • Detection of errors
  • Quantifiedapproach

Objective 6 153. Understanding the Basis

  • Quantified Approach
  • Population vs. Groups
  • Measuring the Difference
  • Stat 101 Counts, Totals, Chi Square and K-S
  • The metrics used

Objective 2 154. Quantified Approach

  • Based onmeasureable differences
  • Population vs. Group
  • Shotgun technique

Objective 2a 155. Detection of Fraud Characteristics

  • Something isdifferentthan expected

Objective 2a 156. Fraud patterns

  • Common theme something is different
  • Groups
  • Group pattern is different than overall population

Objective 2b 157. Measurement Basis

  • Transactioncounts
  • Transactionamounts

Objective 2c 158. A few words about statistics(the s word)

  • Detailed knowledge of statistics not necessary
  • Software packages do the number-crunching
  • Statistics used only to highlight potential errors/frauds
  • Not used for quantification

Objective 2d 159. How is digital analysis done?

  • Comparison of group with population as a whole
  • Can be based on either counts or amounts
  • Difference is measured
  • Groups can then be ranked using a selected measure
  • High difference = possible error/fraud

Objective 2d 160. Demo in Excel of the process

  • Based roughly on the Wake County Transportation fraud
  • Illustrates how the process works, using Excel

161. Histograms

  • Attributes tallied and categorized into bins
  • Countsorsumsof amounts

Objective 2d 162. Two histograms obtained

  • Population and group

Objective 2d 163. Compute Cumulative Amount for each Objective 2d 164. Are the histograms different?

  • Two statistical measures of difference
  • Chi Squared (counts)
  • K-S (distribution)
  • Both yield a difference metric

Objective 2d 165. Chi Squared

  • Classic test on data in a table
  • Answers the question are the rows/columns different
  • Some limitations on when it can be applied

Objective 2d 166. Chi Squared

  • Table of Counts
  • Degrees of Freedom
  • Chi Squared Value
  • P-statistic
  • Computationally intensive

Objective 2d 167. Kolmogorov-Smirnov

  • Two Russian mathematicians
  • Comparison of distributions
  • Metric is the d-statistic

Objective 2d 168. How is K-S test done?

  • Four step process
    • For each cluster element determine percentage
    • Then calculate cumulative percentage
    • Compare the differences in cumulative percentages
    • Identify the largest difference

Objective 2d 169. Kolmogorov-Smirnov Objective 2d - KS 170. Classification by metrics

  • Stratification
  • Day of week
  • Happens on holiday
  • Round numbers
  • Variability
  • Benfords Law
  • Trend lines
  • Relationships (market basket)
  • Gaps
  • Duplicates

Objective 2e 171. Auditors Top 10 Metrics

  • Outliers / Variability
  • Stratification
  • Day of Week
  • Round Numbers
  • Made Up Numbers
  • Market basket
  • Trends
  • Gaps
  • Duplicates
  • Dates

Objective e 172. Understanding the Basis

  • Quantified Approach
  • Population vs. Groups
  • Measuring the Difference
  • Stat 101 Counts, Totals, Chi Square and K-S
  • The metrics used

Objective 2 173. Objective 2 - Summarized

  • Understand why and how
  • Understand statistical basis for quantifying differences
  • Identify ten general tools and techniques
  • Understand examples done using Excel
  • How pattern detection fits in

Next are the metrics 174. Its that time! Session Break! 175. The Top 10 Metrics

  • Overview
  • Explain Each Metric
  • Examples of what it can detect
  • How to assess results

Objective 3 176. Trapping anomalies Objective 3 177. Fraud Pattern Detection Objective 3 Market Basket Stratification Trend Line Holiday Day of Week Duplicates Univariate Gaps Benfords Law Round Numbers Target Group 178. Outliers / Variability Outliers are amounts which are significantly different from the rest of the population 1 - Outliers 179. Outliers / Variability

  • Charting (visual)
  • Software to analyze z-scores
  • Top and Bottom 10, 20 etc.
  • High and low variability (coefficient of variation)

1 - Outliers 180. Drill down to the group level

  • Basic statistics
    • Minimum, maximum and average
    • Variability
  • Sort by statistic of interest
    • Variability (coefficient of variation)
    • Maximum, etc.

1 - Outliers 181. Example Results Two providers (3478421 and 2356721) had significantly more variability in the amounts of their claims than all the rest. 1 - Outliers 18.54 2,311 5463122 23.25 3,421 3546789 87.23 4,536 2356721 342.23 3,243 3478421 Coeff Var N Provider 182. Next Metric

  • Outliers
  • Stratification
  • Day of Week
  • Round Numbers
  • Made Up Numbers
  • Market basket
  • Trends
  • Gaps
  • Duplicates
  • Dates

183. Unusual stratification patterns Do you know how your data looks? 2 - Stratification 184. Stratification - How

  • Charting (visual)
  • Chi Squared
  • Kolmogorov-Smirnov
  • By groups

2 - Stratification 185. Purpose / types of errors

  • Transactions out of the ordinary
  • Up-coding insurance claims
  • Skewed groupings
  • Based on either count or amount

2 Stratification 186. The process?

  • Stratify the entire population into bins specified by auditor
  • Same stratification on each group (e.g. vendor)
  • Compare the group tested to the population
  • Obtain measure of difference for each group
  • Sort descending on difference measure

2 Stratification 187. Units of Service Stratified - Example Results Two providers (2735211 and 4562134) are shown to be much different from the overall population (as measured by Chi Square). 2 Stratification 0.4632 298 2,503 4237869 0.5231 342 3,410 4321089 0.7453 5,234 8,913 4562134 0.8453 7,453 6,011 2735211 D-stat Chi Sq N Provider 188. Next Metric

  • Outliers
  • Stratification
  • Day of Week
  • Round Numbers
  • Made Up Numbers
  • Market basket
  • Trends
  • Gaps
  • Duplicates
  • Dates

189. Day of Week

  • Activity on weekdays
  • Activity on weekends
  • Peak activity mid to late week

3 Day of Week 190. Purpose / Type of Errors

  • Identify unusually high/low activity on one or more days of week
  • Dentist who only handled Medicaid on Tuesday
  • Office is empty on Friday

3 Day of Week 191. How it is done?

  • Programmatically check entire population
  • Obtain counts and sums by day of week (1-7)
  • Prepare histogram
  • For each group do the same procedure
  • Compare the two histograms
  • Sort descending by metric (chi square/d-stat)

192. Day of Week - Example Results Provider 2735211 only provided service for Medicaid on Tuesdays.Provider 4562134 was closed on Thursdays and Fridays.3 Day of Week 0.2189 56 7,905 4237869 0.321 87 5,162 4321089 0.8472 7,746 5,182 4562134 0.9802 12,435 5,404 2735211 D-stat Chi Sq N Provider 193. Next Metric

  • Outliers
  • Stratification
  • Day of Week
  • Round Numbers
  • Made Up Numbers
  • Market basket
  • Trends
  • Gaps
  • Duplicates
  • Dates

194. Round Numbers Its about. Estimates! 4 Round Numbers 195. Purpose / Type of Errors

  • Isolate estimates
  • Highlight account numbers in journal entries with round numbers
  • Split purchases (under the radar)
  • Which groups have the most estimates

4 Round Numbers 196. Round numbers

  • Classify population amounts
    • $1,375.23 is not round
    • $5,000 is a round number type 3 (3 zeros)
    • $10,200 is a round number type 2 (2 zeros)
  • Quantify expected vs. actual (d-statistic)
  • Generally represents anestimate
  • Journal entries

4 Round Numbers 197. Round Numbers in Journal Entries - Example Results Two accounts, 2735211 and 4562134 have significantly more round number postings than any other posting account in the journal entries.4 Round Numbers 0.2189 546 9,549 4237869 0.321 768 8,318 4321089 0.97023 35,324 833 4562134 0.9802 54,637 4,136 2735211 D-stat Chi Sq N Account 198. Next Metric

  • Outliers
  • Stratification
  • Day of Week
  • Round Numbers
  • Made Up Numbers
  • Market basket
  • Trends
  • Gaps
  • Duplicates
  • Dates

199. Made up Numbers Curb stoning Imaginary numbers Benfords Law 5 Made up numbers 200. What can be detected

  • Made up numbers e.g. falsified inventory counts, tax return schedules

5 Made Up Numbers 201. Benfords Law using Excel

  • Basic formula is =log(1+(1/N))
  • Workbook with formulae available athttp://tinyurl.com/4vmcfs
  • Obtain leading digits using Left function, e.g. left(Cell,1)

5 Made Up Numbers 202. Made up numbers

  • Benfords Law
  • Check Chi Square and d-statistic
  • First 1,2,3 digits
  • Last 1,2 digits
  • Second digit
  • Sources for more info

5 Made Up Numbers 203. How is it done?

  • Decide type of test (first 1-3 digits, last 1-2 digit etc)
  • For each group, count number of observations for each digit pattern
  • Prepare histogram
  • Based on total count, compute expected values
  • For the group, compute Chi Square and d-stat
  • Sort descending by metric (chi square/d-stat)

5 Made Up Numbers 204. Invoice Amounts tested with Benfords law - Example Results During tests of invoices by store, two stores, 324 and 563 have significantly more differences than any other store as measured by Benfords Law.5 Made Up Numbers 0.2189 312 74 217 0.321 476 23 432 0.97023 4,735 89 563 0.9802 5,234 79 324 D-stat Chi Sq Hi Digit Store 205. Next Metric

  • Outliers
  • Stratification
  • Day of Week
  • Round Numbers
  • Made Up Numbers
  • Market basket
  • Trends
  • Gaps
  • Duplicates
  • Dates

206. Market Basket

  • Medical Ping ponging
  • Pattern associations
  • Apriori program
  • References at end of slides
  • Apriori Latin a (from) priori (former)
  • Deduction from the known

6 Market Basket 207. Purpose / Type of Errors

  • Unexpected patterns and associations
  • Based on market basket concept
  • Unusual combinations of diagnosis code on medical insurance claim

6 Market basket 208. Market Basket

  • JE Accounts
  • JE Approvals
  • Credit card fraud in Japan taxi and ATM

6 Market basket 209. How is it done?

  • First, identify groups, e.g. all medical providers for a patient
  • Next, for each provider, assign a unique integer value
  • Create a text file containing the values
  • Run apriori analysis

6 Market basket 210. Apriori outputs

  • For each unique value, probability of other values
  • If you see Dr. Jones, you will also see Dr. Smith (80% probability)
  • If you see a JE to account ABC, there will also an entry to account XYZ (30%)

6 Market basket 211. Next Metric

  • Outliers
  • Stratification
  • Day of Week
  • Round Numbers
  • Made Up Numbers
  • Market basket
  • Trends
  • Gaps
  • Duplicates
  • Dates

212. Numeric Sequence Gaps Whats there is interesting, whats not there is critical 8 - Gaps 213. Purpose / Type of Errors

  • Missing documents (sales, cash, etc.)
  • Inventory losses (missing receiving reports)
  • Items that walked off

8 Gaps 214. How is it done?

  • Check any sequence of numbers supposed to be complete, e.g.
  • Cash receipts
  • Sales slips
  • Purchase orders

8 Gaps 215. Gaps Using Excel

  • Excel sort and check
  • Excel formula
  • Sequential numbers and dates

8 Gaps 216. Gap Testing - Example Results Four check numbers aremissing .8 Gaps 1 17548 17546 2 12526 12523 1 10791 10789 Missing End Start 217. Next Metric

  • Outliers
  • Stratification
  • Day of Week
  • Round Numbers
  • Made Up Numbers
  • Market basket
  • Trends
  • Gaps
  • Duplicates
  • Dates

218. Duplicates Why is there more than one? Same, Same, Same, and Same, Same, Different 9 - Duplicates 219. Two types of (related) tests

  • Sameitems samevendor,sameinvoice number,sameinvoice date,sameamount
  • Differentitems sameemployee name,samecity,differentsocial security number

9 Duplicates 220. Duplicate Payments

  • High payback area
  • Fuzzy logic
  • Overriding software controls

9 - Duplicates 221. Fuzzy matching with software

  • Levenshtein distance
  • Soundex
  • Like clause in SQL
  • Regular expression testing in SQL
  • Vendor/employee situations

Russian physicist 9 - Duplicates 222. How is it done?

  • First, sort file in sequence for testing
  • Compare items in consecutive rows
  • Extract exceptions for follow-up

9 - Duplicates 223. Possible Duplicates - Example Results Five invoices may beduplicates .9 - Duplicates 2 1,500.00 2/12/2007 17546 2 2,010.37 8/31/2007 10245 4 3,544.78 6/15/2007 10245 Count Invoice Amount Invoice Date Vendor 224. Next Metric

  • Outliers
  • Stratification
  • Day of Week
  • Round Numbers
  • Made Up Numbers
  • Market basket
  • Trends
  • Gaps
  • Duplicates
  • Dates

225. Date Checking If were closed, why is there Adjusting journal entry? Receiving report? Payment issued? 10 - Dates 226. Holiday Date Testing

  • Red Flag indicator

10 Dates 227. Date Testing challenges

  • Difficult to determine
  • Floating holidays Friday, Saturday, Sunday, Monday

10 Dates 228. Typical audit areas

  • Journal entries
  • Employee expense reports
  • Business telephone calls
  • Invoices
  • Receiving reports
  • Purchase orders

10 Dates 229. Determination of Dates

  • Transactions when business is closed
  • Federal Office of Budget Management
  • An excellent fraud indicator in some cases

10 Dates 230. Holiday Date Testing

  • Identifying holiday dates:
    • Error prone
    • Tedious
  • U.S. only

10 Dates 231. Federal Holidays

  • Established by Law
  • Ten dates
  • Specific date (unless weekend),OR
  • Floating holiday

10 Dates 232. Federal Holiday Schedule

  • Office of Personnel Management
  • Example of specific date Independence Day, July 4 th(unless weekend)
  • Example of floating date Martin Luther Kings birthday (3 rdMonday in January)
  • Floating Thanksgiving 4 thThursday in November

10 Dates 233. How it is done?

  • Programmatically count holidays for entire population
  • For each group, count holidays
  • Compare the two histograms (group and population)
  • Sort descending by metric (chi square/d-stat)

10 Dates 234. Holiday Counts - Example Results Two employees (10245 and 32325) were off the chart in terms of expense amounts incurred on aFederal Holiday .10 Dates 0.2189 312 34 24135 0.321 476 18 17546 0.97023 4,735 23 32325 0.9802 5,234 37 10245 D-stat Chi Sq N Employee Number 235. The Top 10 Metrics

  • Overview
  • Explain Each Metric
  • Examples of what it can detect
  • How to assess results

Objective 3 236. Objective 3 - Summarized

  • Understand why and how
  • Understand statistical basis for quantifying differences
  • Identify ten general tools and techniques
  • Understand examples done using Excel
  • How pattern detection fits in

Next using Excel 237. Use of Excel

  • Built-in functions
  • Add-ins
  • Macros
  • Database access

Objective 4 238. Excel templates

  • Variety of tests
    • Round numbers
    • Benfords Law
    • Outliers
    • Etc.

Objective 4 239. Excel Univariate statistics

  • Work with Ranges
  • =sum, =average, =stdevp
  • =largest(Range,1), =smallest(Range,1)
  • =min, =max, =count
  • Tools | Data Analysis | Descriptive Statistics

Objective 4 240. Excel Histograms

  • Tools | Data Analysis | Histogram
  • Bin Range
  • Data Range

Objective 4 241. Excel Gaps testing

  • Sort by sequential value
  • =if(thiscell-lastcell 1,thiscell-lastcell,0)
  • Copy/paste special
  • Sort

Objective 4 242. Detecting duplicates with Excel

  • Sort by sort values
  • =if testing
  • =if(=and(thiscell=lastcell, etc.))

Objective 4 243. Performing audit tests with macros

  • Repeatable process
  • Audit standardization
  • Learning curve
  • Streamlining of tests
  • Moreefficient and effective
  • Examples -http://ezrstats.com/Macros/home.html

Objective 4 244. Using database audit software

  • Many built-in functions right off the shelf with SQL
  • Control totals
  • Exception identification
  • Drill down
  • Quantification
  • June 2008 article in the EDP Audit & Control Journal (EDPACS) SQL as an audit tool
  • http://ezrstats.com/doc/SQL_As_An_Audit_Tool.pdf

Objective 4 245. Use of Excel

  • Built-in functions
  • Add-ins
  • Macros
  • Database access

Objective 4 246. Objective 4 - Summarized

  • Understand why and how
  • Understand statistical basis for quantifying differences
  • Identify ten general tools and techniques
  • Understand examples done using Excel
  • How Pattern Detection fits in

Next Fit 247. How Pattern Detection Fits In

  • Business Analytics
  • Fraud Pattern Detection
  • Continuous monitoring

Objective 5 248. Where does Fraud Pattern Detection fit in?

  • Business Analytics
  • Fraud Pattern Detection
  • Continuous fraud pattern detection
  • Continuous Monitoring

Right in the middle Objective 5 249. Business Analytics

  • Fraud analytics -> business analytics
  • Business analytics -> fraud analytics

Objective 5 250. Role in Continuous Monitoring (CM)

  • Fraud analytics can feed(CM)
  • Continuous fraud pattern detection
  • Use output from CM to tune fraud pattern detection

Objective 5 251. Objective 6 - Summarized

  • Understand the framework for managing the business risk of fraud
  • Plan, perform and explain statistical sampling in audits
  • Reduce audit costs using data mining, sequential sampling and other sampling techniques
  • Apply SAS 56, the new SAS suite and the revised (2007) Yellow Book.
  • Run, hands-on, the most productive analytic technique (regression analysis).
  • Use data mining to introduce greater efficiency into the audit process, without losing effectiveness.

252. Links for more information

  • Kolmogorov-Smirnov
  • http://tinyurl.com/y49sec
  • Benfords Lawhttp://tinyurl.com/3qapzu
  • Chi Square testshttp://tinyurl.com/43nkdh
  • Continuous monitoringhttp://tinyurl.com/3pltdl

253. Market Basket

  • Apriori testing for ping ponging
  • Temple Universityhttp://tinyurl.com/5vax7r
  • Apriori program (open source)http://tinyurl.com/5qehd5
  • Article Medical ping ponginghttp://tinyurl.com/5pzbh4

254. Excel macros used in auditing

  • Excel as an audit softwarehttp://tinyurl.com/6h3ye7
  • Selected macros -http://ezrstats.com/Macros/home.html
  • Spreadsheets forever -http://tinyurl.com/5ppl7t

255. Questions? 256. Contact info

  • Phone: (919)-219-1622
  • E-mail:[email_address]
  • Blog:http://blog.ezrstats.com