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.