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RECONCILIATION ANALYSIS Of the Forty-Niners Shops
Octavio Urista
Tony Molina
1
Table of Contents About the Forty-Niners Shops: ..................................................................................................................... 2
Project Expectations: .................................................................................................................................... 2
Data: .............................................................................................................................................................. 3
Analysis: ........................................................................................................................................................ 4
Bookstore: ................................................................................................................................................. 5
Bookstore Convenience Store:.................................................................................................................. 7
Beach Hut: ............................................................................................................................................... 10
General Recommendations: ....................................................................................................................... 14
Store-Specific Recommendations: .............................................................................................................. 15
Future Analyses: .......................................................................................................................................... 16
2
About the Forty-Niners Shops: The Forty-Niners Shops is a non-profit auxiliary of California State University, Long Beach (CSULB)
incorporated by the state of California and acts as the commercial arm of the university. The Forty-Niners
Shops include 25 stores both on- and off-campus – with most of the stores located on-campus.
Furthermore, each store has 1-3 shifts, and 1-39 registers.
The store names are as follows:
1 2nd Street Store
2 Art Store
3 Beach Hut
4 Beach Walk
5 Blair Field
6 Bookstore
7 Bookstore Convenience Store
8 CBA & Brotman Hall Carts
9 Chartroom
10 Events Center (Pyramid)
11 Fresco Grill
12 George’s Greek Cafe
13 Library Starbucks
14 Los Alamitos Coffee House
15 Nugget
16 Outpost
17 Outpost Convenience Store
18 Parkside
19 Parkside Coffee House
20 Residence Hall
21 Residence Learning Center
22 Student Union Convenience Store
23 Taco Bell
24 UDP Starbucks
25 Value Transfer Station
At the start of each day, cash registers are funded with a starting bank. At the end of each day, all of the
money in the register is placed in a bag and sent to a central location; at which point, the money is
reconciled.
Project Expectations: Identify trends in overages and shortages with respect to stores, cashiers, and shifts.
Identify inefficiencies with respect to stores.
To accomplish these goals we used box-plots, CUSUM charts, Pareto charts, time-series plots, general
linear models (when model assumptions are satisfied).
3
Data: For this project, we received a data dump of all the activity that is recorded after the reconciling process.
The original data set consisted of 107,723 observations.
The cleaned data set consisted of 99,498 observations.
o Observations with beginning cash = 0 and register reading < 0 were removed.
These were all due to refunds/voids made with no initial money in the drawer.
We nor the accountants can make sense of these.
o Observations with register reading = beginning cash were removed.
These observations contribute no additional information, but they do inflate
certain statistics. For instance, the number of “Okay Reconciliations.”
The data set with significant observations consisted of 6,699 observations.
o An observation should be considered significant by the reconciler if it has an overage (or
shortage) of >$5 (or <-$5).
The data we received was compiled by the person reconciling the deposit. The data contains the
following information:
Bag Closing Date
Bag Reconciliation Date
Starting Bank
Final Register Reading (at shift-end)
Money Made
Shift
Register Number
Additional Comments
Amount Over/Short (computed automatically)
The large volume of significant observations made most of the graphs redundant. For this reason, we
chose to group observations by months.
4
Analysis:
3 stores (Bookstore, Beach Hut, Bookstore Convenience Store, Blair Field) account for about 2/3
of both shortages and overages across all 25 stores.
Residence Learning Center, Fresco Grill, Taco Bell, Residence Hall, Parkside Coffee House, and Los
Alamitos Coffee House all lacked shortages and overages.
There was a total amount of $210,685 in shortages and a total amount of $169,989 in overages
for a total deficit of $40,696.
We narrowed the focus of the rest of our analysis on the Bookstore, Beach Hut, Bookstore Convenience
Store– these 3 stores contributed about 63% of both the shortages and overages.
5
Bookstore -
Shift A contributes the most to both overs and shorts.
This is expected, as the mornings are always the busiest at the Bookstore.
Cashier 11 contributes the most to both overs and shorts.
Left: January and August were the heaviest months with respect to shorts.
This is expected as these are the months when the bookstore receives the most traffic.
As well as this, the bookstore has more seasonal workers around this time.
Right: Without shift D (a shift with <10 observations), all of the shifts have statistically equal
variances. This is what we wish (and expect) to see.
Z
D
CB
C
B
A
250200150100500
P-Value 0.028
P-Value 0.000
Multiple Comparisons
Levene’s Test
Sh
ift
Test for Equal Variances: Avg. Over/Short vs ShiftMultiple comparison intervals for the standard deviation, α = 0.05
If intervals do not overlap, the corresponding stdevs are significantly different.
6
There was significant shifts in January 2011, February 2011, April 2011, and May 2011.
Left: The un-adjusted Xbar/R-charts.
Right: The adjusted Xbar/R-charts.
*Boxplots were not provided due to the large number of observations.
**Test for Equal Variances: Avg. Over/Short vs Cashiers could not be graphically produced because some
cashiers had <3 observations.
*** Regression could not be run as data did not satisfy the normality assumption (with and without
Johnson Transformation).
Note: Box-Cox transformation cannot be performed on negative data.
Month**
Year**
April
Septe
mber
Febru
ary
July
Dec
ember
May
October
Mar
ch
Augus
t
Janu
ary
2015
2014
2014
2013
2012
2012
2011
2011
2010
2010
5000
2500
0
-2500
-5000
-7500
-10000
Cu
mu
lati
ve S
um
0
UCL=3577
LCL=-3577
CUSUM Chart of Bookstore
201520142013201220112010
2
0
-2
-4
Year
Sa
mp
le M
ea
n
__X=-0.535
UCL=2.869
LCL=-3.938
201520142013201220112010
30
20
10
0
Year
Sa
mp
le R
an
ge
_R=10.11
UCL=18.36
LCL=1.861
1
Tests are performed with unequal sample sizes.
Xbar-R Chart of Avg. Over/Short for Bookstore
2015201420122010
2
0
-2
Year
Sa
mp
le M
ea
n
__X=-0.585
UCL=1.681
LCL=-2.852
2015201420122010
12
8
4
0
Year
Sa
mp
le R
an
ge
_R=6.73
UCL=12.22
LCL=1.24
Results exclude specified rows: 13:24, 37:48
Tests are performed with unequal sample sizes.
Xbar-R Chart of Avg. Over/Short for Bookstore
7
Bookstore Convenience Store:
It is strange that shift B contributes as much to shortages, despite its small contributions to the
amount overages.
Cashier 21 contributes most to both overages and shortages.
Left:
o There were many unexpected spikes.
Right:
o There was a lot of large shortages in September of 2013 and thereon after.
Mo.
Year
May
Dec
ember
July
Febru
ary
Septe
mbe
r
April
Novem
ber
June
Janu
ary
August
2015
2014
2014
2014
2013
2013
2012
2012
2012
2011
500
0
-500
-1000
-1500
-2000
-2500
-3000
Cu
mu
lati
ve S
um
0
UCL=519
LCL=-519
CUSUM Chart of Mean Over/Short
8
Left:
o We see that cashier 22 has much more variation than the other shifts.
o Cashiers 21-23 all have fairly large outliers, with cashier 22 being of special interest.
o The median is at about 0 for all 4 cashiers, as is desired.
Right:
o We see that all shifts have about the same variance.
o Shifts B and Z have fairly large outliers, with shift Z being of special interest.
o The median is at about 0 for all 3 shifts, as is desired.
Based on Levene’s Test, all of the shifts have statistically equal variances.
Based on Levene’s Test, all of the cashiers do not have statistically equal variances.
2322211
1000
500
0
-500
Cashier
Avg
. O
ver/
Sh
ort
Boxplot of Avg. Over/Short
ZBA
1000
500
0
-500
Shift
Avg
. O
ver/
Sh
ort
Boxplot of Avg. Over/Short
23
22
21
1
7006005004003002001000
P-Value 0.000
P-Value 0.042
Multiple Comparisons
Levene’s Test
Cash
ier
Test for Equal Variances: Avg. Over/Short vs CashierMultiple comparison intervals for the standard deviation, α = 0.05
If intervals do not overlap, the corresponding stdevs are significantly different.
Z
B
A
6005004003002001000
P-Value 0.048
P-Value 0.109
Multiple Comparisons
Levene’s Test
Sh
ift
Test for Equal Variances: Avg. Over/Short vs ShiftMultiple comparison intervals for the standard deviation, α = 0.05
If intervals do not overlap, the corresponding stdevs are significantly different.
20152014201320122011
20
0
-20
-40
Year
Sa
mp
le M
ea
n
__X=-10.64
UCL=14.45
LCL=-35.73
20152014201320122011
150
100
50
0
Year
Sa
mp
le R
an
ge
_
R=59.8
UCL=115.2
LCL=4.5
1
1
Xbar-R Chart of Months in Year
Tests are performed with unequal sample sizes.
201520142011
20
0
-20
-40
Year
Sa
mp
le M
ea
n
__X=-9.58
UCL=13.74
LCL=-32.91
201520142011
120
80
40
0
Year
Sa
mp
le R
an
ge
_R=55.6
UCL=107.0
LCL=4.2
Xbar-R Chart of Months in Year
Results exclude specified rows: 6:29
Tests are performed with unequal sample sizes.
9
Left: The un-adjusted Xbar/R-charts.
Right: The adjusted Xbar/R-charts.
The R-Sq (adj) is very low. That is, the variables in our model account for 0% of the variation in the
data. It is best to ignore this model.
Note: This is the data after having performed the Johnson Transformation
10
Beach Hut:
Shift Z contributed the largest amount of shortages, despite having among the least overages.
Cashier 3 contributed the most to both overages and shortages.
Left:
o There were many unexpected spikes. It is quite surprising to see such a downward trend
in the latter months.
Right:
o The CUSUM chart indicates that Beach Hut is doing better than the previous two years.
It is still doing quite poorly, however.
Month
Year
April
October
April
October
April
October
Febru
ary
Augus
t
Febru
ary
July
Janu
ary
2015
2014
2014
2013
2013
2012
2012
2011
2011
2010
2010
100
0
-100
-200
-300
Cu
mu
lati
ve S
um
0
UCL=52.1
LCL=-52.1
CUSUM Chart of Avg. Over/Short
11
Left:
o Shift D and Z appear to be particularly worrisome, however, our Pareto charts reveals
small contributions from both D and Z. We need not worry.
o The rest of the shifts appear to have a proper median.
o There is a couple of worrisome outliers.
Right:
o Cashier 4 appears to have a large variance and low median, however, our Pareto charts
reveal small contributions from this cashier. We need not worry.
Based on Levene’s Test, all of the cashiers do not have statistically equal variances.
ZDCB - Change BagCBA
0
-200
-400
-600
-800
Shift
Avg
. O
ver/
Sh
ort
Boxplot of Avg. Over/Short
1654321
0
-200
-400
-600
-800
Cashier
Avg
. O
ver/
Sh
ort
Boxplot of Avg. Over/Short
4
3
2
1
2000150010005000
P-Value 0.401
P-Value 0.010
Multiple Comparisons
Levene’s Test
Cash
ier
Test for Equal Variances: Avg. Over/Short vs CashierMultiple comparison intervals for the standard deviation, α = 0.05
If intervals do not overlap, the corresponding stdevs are significantly different.
201520142013201220112010
10
0
-10
-20
-30
Year
Sa
mp
le M
ea
n
__X=-9.54
UCL=9.91
LCL=-29.00
201520142013201220112010
120
90
60
30
0
Year
Sa
mp
le R
an
ge
_R=52.2
UCL=97.3
LCL=7.1
1
1
Tests are performed with unequal sample sizes.
Xbar-R Chart of Avg. Over/Short for Beach Hut
2015201420122010
10
0
-10
-20
Year
Sa
mp
le M
ea
n
__X=-6.88
UCL=11.27
LCL=-25.02
2015201420122010
100
50
0
Year
Sa
mp
le R
an
ge
_R=48.7
UCL=90.8
LCL=6.6
1
Results exclude specified rows: 12:23, 34:45
Tests are performed with unequal sample sizes.
Xbar-R Chart of Avg. Over/Short for Beach Hut
12
Left: The un-adjusted Xbar/R-charts.
Right: The adjusted Xbar/R-charts.
Note: This model contains Shift D (which has only 2 observations, both of which are outliers).
Further note: Shift D has a very large VIF.
Removing Shift D is recommended and will likely make other variables significant and improve the
model’s significance.
13
27.13% is a decent R-squared for economic data.
We note that Shifts add statistically significant variation to the model – both shifts A and B are
statistically significant at the 0.05 alpha level. Interestingly, they both have positive coefficients.
We further note that Cashiers also add statistically significant variation to the model – Cashiers 1,
2, and 3 are statistically significant at the 0.10 alpha level. Again, they both have positive
coefficients.
Lastly, we note that neither January nor August were statistically significant.
Note: This is the data after having performed the Johnson Transformation
14
General Recommendations: Do not have cashiers reconcile their own drawers.
o As we saw in the Pareto charts, many stores do not contribute any shortages or overages.
There should be some natural variance in overages and/or shortages.
Tom (an accountant for CSULB’s Forty-Niner shops) attributes this to the fact that
these locations reconcile their own drawers.
Having experience as a cashier with and without a reconciliation system, it is
noticeable that there are less recorded “overages” and “shortages” in a system
where cashiers reconcile their own drawers.
Have managers train employees how to properly void orders and handle checks.
o Consider these entries for the Bookstore (note: there’s many more):
“check was counted twice $3073.91 Entered by mcajucom on 1/21/2015 5:35:59
PM I think what happen is they ran the check twice $3073.91 and also void
transaction of $359.00. Steve was showing me something about the void
transaction. 1-21-15 Entered by mcajucom on 1/21/2015 3:40:48 PM”
“missing 3 checks Entered by mcajucom on 1/14/2011 1:09:03 PM”
“missing 3 checks for 845.61 Entered by mclaussen on 6/25/2010 10:26:35 AM”
“check for $752.10 rang up twice Entered by ccurd on 1/18/2014 11:25:38 AM”
Require clearer comments from reconcilers.
o “not $533.00 its $553.00 Entered by mcajucom on 9/21/2010 10:54:51 AM bag 2A was
over $533.00 Entered by mcajucom on 9/21/2010 10:53:42 AM”
On multiple occasions reconcilers simply state that the amount entered is
incorrect. This is quite worrisome.
o “Nebraska problem Entered by mcajucom on 12/21/2010 3:42:23 PM hand written
charges $127.72”
We, or anyone looking back, will be unable to make any sense of this.
Do not allow any cashiers to use each other’s registers under any circumstances.
o It was often the case that one cashier would balance out another cashier in a different
shift. Consider these entries below (note: there’s many more):
“balances with 7B Entered by ccurd on 8/27/2013 9:51:35 AM”
“balances with 6B Entered by ccurd on 8/27/2013 9:44:03 AM”
“balances with 8B Entered by ccurd on 8/27/2013 9:59:37 AM”
“balances with 3B Entered by ccurd on 3/26/2014 10:50:12 AM”
Lessen the number of unnecessary cashiers and shifts recorded.
o Consider the Bookstore:
There are not 39 registers in the bookstore. How are there 39 cashiers?
Some of the cashiers and shifts had <10 observations
(Cashiers: 13, 14, 36-38, 99 & Shift: D).
Is there a reason why these had to be categorized distinctly?
Eliminate the possibility of creating incomplete forms.
o We deleted many observations with missing values.
This hurts future statistical analysis.
15
Store-Specific Recommendations: Bookstore:
o Specific cashiers to look at:
Bookstore Cashiers 11, 17 and 12 (based on Pareto Charts)
o Specific shifts to look at:
A (based on Pareto charts)
o This store performed poorly in January and December.
We understand this is likely due to the large volume of seasonal workers during
this time period. Consider longer training periods or better training methods.
Bookstore Convenience Store:
o Specific cashiers to look at:
21 (based on Pareto charts),22 (based on box-plots)
o Specific shifts to look at:
B (based on Pareto charts), Z (based on box-plots)
o This store performed poorly in almost each month.
Beach Hut:
o Specific cashiers to look at:
3 (based on Pareto charts and box-plots)
o Specific shifts to look at:
A, Z (based on Pareto charts and box-plots)
o This store performed poorly in the latter half of the year.
16
Future Analyses: Only Octavio will be returning next semester so he will be the person performing these analyses in the
future.
Use data mining techniques to filter out transactions that contained refunds and voids (which
caused them to appear as “short”).
o We did not provide a list of outliers due to the fact that we could not distinguish
efficiently whether an outlier was due to cashier error, void, or refund. This can be done
efficiently with data mining techniques.
Use regression analysis techniques as opposed to general linear model techniques so that
predictions can be made.
Use time-series techniques to analyze the data.
Use nonparametric techniques that may be more robust for data of this type.