Car
Build Dates Revisited
Chris Henze extracted the following data from an undated
article. He obtained it from the January-February 1990 issue of the American
Motoring Magazine. It attempts to
correlate the sequence number with a production date.
In the article Chris makes some assumptions from which he derives a
methodology to determine an approximate build date of American Motors vehicle
built in the Kenosha plant between August 1968 and July 1969.
Not having access to the original article it is not possible for me to
determine if this is actually the Kenosha plant but seems like a reasonable
conclusion. I have expanded the
data to include the day of the week and the number of cars built between the
dates specified.
The methodology indicated in Chris's article is good but the assumptions
upon which it is based are flawed when the data is carefully examined.
His first assumption is that all the dates represent an end of week but
does not specify what the workweek was. Further
he assumes a seven-day work week and that can be seen is not true.
Most end-of-week dates are Fridays but a significant number of others are
Saturday. Production ramp up and
termination also introduce non-typical dates and quantities.
A close examination of the data will show some startling information as
described in the paragraphs following the expanded data.
AMC
production for 1968 and 1969
Day
Date
East Line
West Line Month/Year
---
----------
---------
--------- --------------
Tues
07-09-1968
E-0000030
W-001018 July
1968
---
----------
6
2455
--------------
Fri
08-16-1968
E-0000036
W-003473
1183
1865
Mon
08-26-1968
E-0001219
W-005338 August
1968
2399
2788
Fri
08-30-1968
E-0003618
W-008126
---
----------
2279
2267
--------------
Fri
09-06-1968- E-0005897
W-010393
2774
3391
Saturday
09-14-1968
E-0008671
W-013784
2891
2894
September 1968
Friday
09-20-1968
E-0011562
W-016678
2914
2884
Friday
09-27-1968
E-0014476
W-019562
------
----------
2901
-------- --------------
Friday
10-04-1968
E-0017377
W-022376
2851
2877
Friday
10-11-1968
E-0020228
W-025253
2908
2665
October 1968
Friday
10-18-1968
E-0023136
W-027918
3275
3463
Saturday
10-26-1968
E-0026411
W-031381
------
----------
2921
2874
--------------
Friday
11-01-1968
E-0029332
W-034255
2911
2875
Friday
11-08-1968
E-0032243
W-037130
2915
2742
Friday
11-15-1968
E-0035158
W-039872 November
1968
2916
2887
Friday
11-22-1968
E-0038074
W-042759
1245
1704
Wednesday
11-27-1968
E-0039319
W-044463
-------
----------
2921
2799
-------------
Friday
12-06-1968
E-0042240
W-047262
2892
2608
Friday
12-13-1968
E-0045132
W-049870
2843
2584
December 1968
Friday
12-20-1968
E-0047975
W-052454
0
0
Friday
12-27-1968
No Production
------
----------
0
0
------------
Friday
01-03-1969
No Production
2403
2883
Friday
01-10-1969
E-0050378
W-055337
2599
2001
Friday
01-17-1969
E-0052977
W-057338 January
1969
2920
2881
Friday
01-24-1969
E-0055897
W-060219
2922
2575
Friday
01-31-1969
E-0058819
W-062794
------
----------
2685
2658
-------------
Friday
02-07-1969
E-0061504
W-065452
2912
2666
Friday
02-14-1969
E-0064416
W-068118 February
1969
2804
2917
Friday
02-21-1969
E-0067220
W-071035
2913
0
Friday
02-28-1969
E-0070133
W-071035
----------
2913
5518
-------------
Friday
03-07-1969
E-0073046
W-076553
2927
0
Friday
03-14-1969
E-0075973
W-076553
2905
2807 March 1969
Friday
03-21-1969
E-0078878
W-079360
2905
2003
Friday
03-26-1969
E-0081783
W-081363
------
----------
2330
2168
-------------
Friday
04-04-1969
E-0084113
W-083531
3259
1881
Saturday
04-12-1969
E-0087372
E-085412
2905
3890 April 1969
Friday
04-18-1969
E-0090277
W-089302
3161
2844
Saturday
04-26-1969
E-0093438
W-092146
--------
----------
2408
2889
-------------
Friday
05-02-1969
E-0096346
W-095035
3207
2775
Saturday
05-10-1969
E-0099553
W-097810
3260
2587
Saturday
05-17-1969
E-0102813
W-100397 May
1969
2801
2877
Friday
05-23-1969
E-0105614
W-103274
2330
2308
Thursday
05-29-1969
E-0107944
W-105574
--------
----------
2899
2825
-------------
Friday
06-06-1969
E-0110843
W-108399
3233
2799
Saturday
06-14-1969
E-0114066
W-111198
2878
2784 June 1969
Thursday
06-20-1969
E-0116944
W-113982
2897
2827
Friday
06-27-1969
E-0119841
W-116809
-------
----------
1719
2285
-------------
Thursday
07-03-1969
E-0121560
W-119094
674
2878
Friday
07-11-1969
E-1222324
W-121972 July
1969
0
2166
Thursday
07-17-1969
E-1222324
W-124138
--------
----------
---------
-------- ------------
After looking at the statistical data
and analyzing it the following facts can be determined:
1
The average number of cars built on the East line during a five-day week
is 2,842.
2
The average number of cars built on the West line during a five-day week
is 2,784.
3
The average number of cars built on the East line during a six-day week
is 3,281.
4
The average number of cars built on the West line during a six day week
is 3,581.
5
8/26/1968 was a Monday. Production
ramp up and line shakedown period.
6
9/14/1968 was a Saturday. East
line production is close to five-day average.
Approximately 607 more cars than the five-day average were produced on
the West line
7
10/26/1968 was a Saturday. Approximately
433 more cars than the five-day average were produced on the East line and 697
more cars than the five-day average were produced on the West line.
8
11/27/1968 was a Wednesday. Thursday
the 27 was Thanksgiving. This week
only had three days of production for both the East and West line.
9
4/12/1969 was a Saturday. Approximately
417 more cars were produced this week on the East line than the five-day
average. The West line was below average.
10
4/26/1969 was a Saturday. Approximately
319 more cars were produced on the East line than the five-day weekly average. The West line production was close to the five-day average.
11
5/10/1969 was a Saturday. Approximately
365 more cars were produced on the East line this week than an average five-day
week. The West line production was
slightly below normal for a five-day week.
12
5/17/1969 was a Saturday. Approximately
418 more cars were produced this week than in an average five-day week.
The West line produced slightly less than average for a five-day week.
13
5/29/1969 was a Thursday and about 512 fewer cars were produced this week
on the East line and about 484 fewer cars on the West line.
There were only four days of production this week.
14
6/14/1969 was a Saturday and about 381 cars more than the five day
average were produced this week on the East line.
Production on the West line was about normal for a five-day week.
151
6/20/1969 was a Thursday. A
normal five-day week production was accomplished in four days.
16
7/3/1969 was a Thursday. Four
days of production and only 1719 cars were produced.
The end of 1969 production was coming.
17
7/17/1969 was a Thursday. There
was no production on the East line and only 2166 cars produced on the West line.
This is the end of production for 1969 vehicles at this plant.
Considering
the facts derived from the data the following can be inferred or deduced:
1
Not all production weeks ended on a Friday and the plant did not run on a
seven day per week schedule. Eleven
weeks in the data ended on a Saturday and thirty-six ended on a Friday.
Logic says that the standard production week was five days of two
eight-hour shifts. The extra
production required an extra shift/s that was added on Saturday.
2
An average week was composed of five days of two shifts each day.
American Motors produced on average 2842 cars each five-day week on the
East line and 2,784 cars per five-day week on West line.
3
An average of 568 cars were produced during each five-day week on the
East line and 557 were produced on an average five-day week on the West line
4
An average of 538 cars were produced on the East line in a six-day week
and an average of 597 cars were produced on the West line in a six-day week.
There were seven weeks in the two years of production that saw production
on a Saturday.
5
The data indicates that when production occurred on a Saturday, both
lines were not necessarily open. For
the week ending Saturday 9/14/1968 the East line produced an average number of
cars for a five-day week but the West line produced about 290 more cars than
average indicating that only the West line was open.
For the week ending Saturday 10/26 1968 the East line produced about 430
more cars than average and the West line produced about 660 more cars indicating
that both lines were open that day. For
the week ending Saturday 4/12/69 the East line produced 415 more than the five
day average but the West line produced fewer than its five day average
indicating that only the East line was open.
Before the production day can be inferred you must first determine which
line on which your car was built and how many days it was in operation.
Once this information is determined the correct divisor can be used to
determine day of the week. If your
sequence number begins with an E it was assembled on the East line and if a W
the West line. As an example, my
1969 AMX has a sequence number of E034735.
Therefore it was built sometime during the production week of 11/11 1968.
Subtracting the beginning and ending numbers indicates that approximately
583 cars were produced per day on the East line.
Interpolation suggests that my car was built on Friday the 15th
of November 1968.
The above data and conclusions are based upon hard facts such as
dates, Holidays and other items that are easy to determine.
There might be other factors such as a strike although the data would not
suggest it.