AT&T's Strategic Plan of Managing for Quality

The following appeared in the September, 1997, issue of recording my recollec- QUALITY PROGRESS: tions. Such is the purpose of what follows. First, EARLY SQC: some background. A HISTORICAL SUPPLEMENT AT&T's strategic plan of managing for quality

Following Alexander Gra- In the 1920s and 1930s, there was ham Bell's invention of the telephone, the newly Western Electric, its Hawthorne Works, and formed American Tele- a committee puzzling over how to use statis- phone and Telegraph Company (AT&T) created tics to solve quality problems. regional telephone companies and a Long Lines Department to provide BY URAN J. M. J universal telephone ser- I am currently writing my statistical quality control vice. This required a huge memoirs, literally racing or SQC. array of facilities. When the clock to complete AT&T set out to build them before my time runs That initiative got under those facilities it faced an out. (I will be 93 years old way in late 1925. I was array of familiar quality in December of this year.) then 21 years old. Many people worked on that problems — interchange- Volume two of those same initiative, but all of ability, standardization, memoirs includes the them were older than I, so precision, reliability, and mid-1920s, when, as a now I may well be the sole so on — but on a scale young engineer at West- survivor. without precedent in hu- ern Electric's Hawthorne man history. It solved Works, I was drawn into a While writing those mem- those problems by innova- Bell Telephone Laborato- oirs it became evident that tions in organization de- ries initiative to make use some of the events that sign and in managing for of the science of statistics took place at Hawthorne quality: for solving various prob- during those early years  It created a captive lems facing Hawthorne's never became a part of the source of supply — West- Inspection Branch. The literature of SQC. I have ern Electric Company end results of that initia- concluded that I should (Western) — to build the tive came to be known as help to fill that gap by hardware.  Within Western it cre- a remedy they proposed quirements." These were ated an elite corps of sci- creating a new, "indepen- passed on to Hawthorne's entists and engineers to dent" organization to in- Development Branch, do product research and spect Western's products. which converted Bell development of the hard- That would have been a Labs' concepts into de- ware and circuitry. (This costly duplication of signs suitable for manu- corps later became an Western's product inspec- facture. In addition it de- AT&T subsidiary — Bell tion. AT&T's top execu- vised many of the pro- Telephone Laboratories or tives rejected this propos- cesses used for making Bell Labs.) al; instead they set up an the products. independent measure of  It established mea- Western's quality as well Hawthorne's Technical sures of the quality of ser- as the quality survey ap- Branch also played a criti- vice provided to sub- proach. cal role. It produced and scribers. published the shop draw- Hawthorne's strategic ings ("blue prints") de-  It established a system plan at managing for scribing the products and of data feedback on quali- quality including the quality "tol- ty of service and on field erances." The Technical quality failures. I joined Western in June Branch had the added job 1924. At that time virtual- of planning for manufac-  It established means ly all of its manufacture ture. For each piece part for measuring the quality was done in the huge and end product, it listed of products produced by Hawthorne Works in the tasks (operations) to Western. Chicago, IL, where I was be performed and in what employed. Most of my  It created a "quality sequence, along with first two years were spent survey" — an audit — to what tools and gages to as a troubleshooter; I in- review the effectiveness of use, safety precautions, vestigated quality com- AT&T's overall system of and so on. The resulting plaints from the shop and managing for quality. plans were published as from the field. It was an written "layouts." These and other innova- informative job; from it I tions were the result of learned which functions The end products of those much discussion within played roles that were es- branches — specifications, the upper levels of AT&T. sential to producing quali- designs, blue prints, lay- For example, early in the ty products. outs — collectively be- life of AT&T some tele- came the quality code of Bell Labs' product re- phone companies were conduct, a body of indus- search and development unhappy with the quality trial law to be obeyed by produced "engineering re- of Western's products; as all at Hawthorne.

2 The most visible role of at- tories to calibrate and Conflict in priorities taining quality was maintain the accuracy of played by the Operating the many mechanical The quality strategies de- Branch. It did the hand- gages, electrical meters, signed by AT&T and s-on work of making the and test equipment. There Hawthorne were effective. hardware, and it em- were also staff depart- The end products were of ployed most of ments to do planning and high quality, but that re- Hawthorne's people. It analysis related to quality. sult was achieved by was responsible for obey- It took a lot of people to brute force and at high ing the quality laws: per- be the guardian of quality. cost. Part of that cost was form the tasks set out in At the peak of the eco- the army of inspectors the layouts; use the pre- nomic boom (1929), the along with their support scribed machines, tools, Inspection Branch em- services. Far greater was and gages; and make the ployed about 5,200 people the cost of redoing prior product meet the toler- out of the total work. I estimate that ances demanded by speci- Hawthorne population of about a third of fications, blue prints, and about 40,000. Hawthorne's efforts con- other quality standards. sisted of redoing: scrap- ping or repairing defec- My employer within tive products, resolving Hawthorne was the In- field failures, trou- spection Branch: "the bleshooting, making up guardian of quality." It in- for shipping delays, and spected and tested all so on. (Such wastes were products to assure confor- common to most indus- mance to quality require- tries.) ments. Inspection and test took place at all stages of Those wastes were largely product progression: raw traceable to conflicting materials, work in priorities inherent in process, and finished Hawthorne's strict func- goods. The truckers had tional organization. No orders to deny transport one was against quality. to any load that lacked an Life was more agreeable inspection stamp. for all if nothing were defective. Yet during the Most Inspection Branch mid-1920s, the top priori- employees did inspection ty of managers in the Op- and test of the product. erating Branch was not to Others worked in labora-

3 attain product quality; it As shop troubleshooter I to enable the chips from was two other things: ran into many cases in the tapping operation to which quality suffered drop into the bin of fin-  The top priority was to due to the higher priority ished parts. Those chips meet schedules. AT&T's of meeting schedules and added to his piecework business was expanding, maintaining earnings. For earnings, since the count- and the demand for more example: ing of the amount of work telephone equipment was produced was done by intense. At the time,  An inspector sampled weight. Hawthorne was virtually a load of machined rubber AT&T's sole source of parts and found a high AT&T and use of proba- supply, so the entire Op- percent to be cracked. As bility theory erating Branch hierarchy it turned out, the milling was under intense pres- machine operator had re- AT&T's applications of sure to meet the sched- ported to his supervisor probability theory can be ules. That pressure per- that many parts were traced to M. C. Rorty's sisted until the Great De- cracking when they were seminal memorandum pression. clamped in the fixture. dated Oct.22, 1903, "Ap- The supervisor called the plication of the Theory of  The second priority (of maintenance department, Probability to Traffic the Operating Branch) which estimated that it Problems." An early appli- was to maintain piece- would take two days to cation was to the problem work earnings. AT&T's repair the fixture. There- of how many idle trunk policies included enlight- upon the supervisor told lines should be provided ened human relations and the operator to run the job for subscribers. In theory (for those days) generous anyway in order to meet it was possible for all sub- employee benefits, Shop the schedule. scribers to need an idle workers were paid by the trunk line at precisely the hour, but with a piece-  An assembly depart- same time. In practice, work addendum that de- ment complained of nu- only a few percent of sub- pended on how much merous electrical short cir- scribers needed lines si- they produced. The em- cuits in its final product multaneously. Use of phasis on piecework earn- due to metal chips from probability theory became ings no doubt stemmed one of the piece parts. I an aid to striking a bal- from Hawthorne's dread traced the chips to a tap- ance that provided good of labor unrest and worse ping operation (it cut service at optimum cost. yet, labor unions. The threads into the copper most dreaded nightmare bushings of that piece The first AT&T applica- was work stoppages. part). The workman had tion of probability theory made an ingenious chute to inspection problems

4 was by C. N. Frazee in As part of his training, "scientific" approach, so 1916.i Frazee used the Lancaster visited some of the young trainee found Poisson exponential as the inspection depart- himself serving as an in- early as 1923 to calculate ments. He noted that in- formal consultant to those sample sizes and operat- spection practice varied inspection supervisors. ing characteristic (OC) widely. Some depart- curves. (I have a copy of ments inspected 100% of Lancaster's activities came his memo of Jan. 3, 1923, the product; others in- to the attention of A. T. which includes many OC spected only a sample. Wood, personnel manager curves as well as curves Moreover, the extent and of the Inspection Branch, for determining sample the methods of sampling who then asked Otto Car- sizes.) AT&T employed differed from one depart- penter, chief of the Col- Poisson's exponential as ment to another. lege Student Training De- early as 1908.ii Cumulative partment, if Lancaster curves of the Poisson dis- Lancaster inquired into could be made available tribution were published the reasons for those dif- to conduct training cour- in the Bell System Techni- ferences. The supervisors ses in statistical methods cal Journal by G. A. explained some differ- for all inspection supervi- Campbelliii and by Frances ences on the grounds of sors. Carpenter and Lan- Thorndike.iv seriousness of the defects; caster were willing but 100% inspection tended to other events intervened. Hawthorne and use of be applied to products in- Lancaster finished his probability theory volving critical defects training course and be- whereas sampling was came a supervisor in the A hitherto unpublished usually applied to less se- Training Department it- contribution to SQC took rious defects. However, self. Some activity contin- place at Hawthorne start- Lancaster challenged ued between the Inspec- ing in 1922. The contribu- some practices, including tion Branch and the Col- tor was A. P. Lancaster, the rationale of sampling. lege Training Department, who had a bachelor's of In those days sampling but this was interrupted science degree in electrical was done by rule of by Lancaster's temporary engineering from Texas thumb: 10% or whatever. transfer to Western's Engi- A&M University. He neering Department in joined Western in July Lancaster's schooling had New York (soon to be- 1922 as a trainee at exposed him to rudimen- come the Bell Telephone Hawthorne. He remained tary statistics, and he dis- Laboratories). with Western until his re- cussed use of probability tirement as senior vice theory with the inspection During his assignments in president in November supervisors. Some of them New York (January to 1964. showed interest in this June 1924), Lancaster took

5 a course in probability  Rating of quality of rant of probability theory. theory under Thornton C. manufactured product to Few employees had train- Fry. As a result, Lancaster be improved by use of re- ing in the subject, and was able to pose to Fry finements that had been even those lacked knowl- some of the sampling evolved at Bell Labs edge in depth. To fill this problems encountered by vacuum, Robertson asked Hawthorne's Inspection Robertson responded pos- Lancaster to prepare and Branch. This feedback to itively. A joint Committee teach a training course to Fry may well have sensi- on Inspection Statistics be given to a selection of tized Bell Labs as to the and Economy was set up Inspection Branch engi- opportunities for applying to explore the proposals neers and managers. statistical methodology to and to take appropriate factory problems. Up to action. It was agreed to Lancaster was willing but that time no one at Bell meet several times each he also was concerned Labs had come forward year and to follow an or- that he might lack the with proposals that might derly procedure: agendas depth needed to provide involve such applications. prepared in advance, min- answers to the wide vari- utes to be published, and ety of problems that Bell Labs' initiative "homework" to be done would be brought up by between meetings. The the attendees. When he In late 1925, R.L. Jones, the Bell Labs delegation in- sought help from Dean head of Bell Labs' Inspec- cluded men who later be- Spence of the Liberal Arts tion Engineering Depart- came well-known in qual- and Humanities Depart- ment, proposed to W. L. ity control history: George ment of the University of Robertson, head of D. Edwards, Walter A. Chicago, Spence nominat- Hawthorne's Inspection Shewhart, Harold F ed someone whom he Branch, that the two orga- Dodge, and others. One of called "a brilliant young nizations jointly study these others was Donald mathematician" — Walter three proposals pertinent A. Quarles, whom I have Bartky — who was then to product quality: always regarded as the in- working on his master's tellectual leader of the del- program. In Lancaster's  Sampling inspection to egation. He went on to a view, a wiser selection be done scientifically brilliant career in industry could not have been through use of probability and government, includ- made. Bartky, a student of theory ing service as deputy sec- modest means, accepted a  Analysis of inspection retary of the U.S. Depart- part-time arrangement in data to be aided by use of ment of Defense. which he and Lancaster the newly invented "con- collaborated in preparing Hawthorne soon discov- trol chart" the course. ered it was woefully igno-

6 In late 1925 Bartky gave a possessive about the train- level expressed in percent course in probability theo- ing courses and insisted defective. This was named ry to about 20 engineers on conducting them with the "lot tolerance percent and managers selected Bartky but without the defective." from the Inspection continued participation of Branch. I was among the Training Department.  Sampling plans would those selected. Lancaster was decidedly be designed so as to give less than enthusiastic over any lot containing the tol- The heads of the Inspec- the loss of his brain child, erance percent defective a tion Branch also decided and his confrontation with probability of 0.1 of being to organize specially to Vacin was decidedly less accepted by the sampling provide support to the than harmonious. In the plan — the "consumer's Hawthorne members of process of ousting Lancas- risk" would be 0.1. the committee. Their feel- ter, the Inspection Branch  Sampling from ing was that the almost lost Bartky, who any lot would be Hawthorne members felt a sense of loyalty to done at random. would be unable to carry the Training Department. their share of the commit- It took a good deal of per-  A single sampling tee load unless they were suasion by Lancaster to would decide whether the backed up by a staff with keep Bartky in the fold. lot was acceptable or not. capability in probability (In due course Bartky was theory. To this end they retained as a consultant The foregoing approach created a new depart- by one of Western's devel- was in line with Bell Labs' ment: the Inspection Sta- opment departments.) prior experience with tistical Department. It sampling. That experience consisted of a department The proposals for sam- came chiefly from prod- head, E. F. Vacin, and two pling ucts bought by Western in engineers, R. J. Bradford its role as a central pur- The sampling plans pro- and J. M. Juran. The new chasing service for the posed by Bell Labs were department was no doubt telephone companies. An built around a lot-by-lot among the first such de- example of such pur- sampling concept, as fol- partments in industrial chased products was tele- lows: history. phone poles. (In those days, buyers tended not to Creation of the Inspection  Sampling would be become involved with Statistical Department done on logical identifi- suppliers' production pro- also resulted in Lancaster able lots. cesses.) In contrast, leaving the scene. The In-  For each product type Hawthorne was a manu- spection Branch (in the there would be estab- facturer deeply involved person of Vacin) became lished a tolerable quality in production processes,

7 and hence faced many limiting percent defective Hawthorne readily agreed sampling problems that itself. At Hawthorne there to use of 0.1 as a value for were outside the experi- were endless debates be- consumer's risk where fin- ence of Bell Labs. These tween component depart- ished product was con- differences in experience ments and assembly de- cerned. No one wanted resulted in some lively partments on how high to poor quality to go to cus- discussions and in some set this limit. The most tomers. However, revisions of Bell Labs' pro- usual approach for inter- Hawthorne strongly op- posals. The main areas of nal defects was through posed a risk of 0.1 as ap- discussion are set out in negotiation between the plied to work in process; it the following. contesting production de- contended that product of partments, with inspec- break-even quality should Concept of the lot tion departments acting as have a consumer's risk of mediators. In important 0.5. I recall preparing a Bell Labs' proposal as- cases, they might compute proposal along this line sumed the existence of the "break-even point" — for consideration by the natural or logical "lots." that percent defective at committee. It was prompt- For many Hawthorne which the cost of finding a ly rejected, resulting in an products this was a valid defect was equal to the impasse. For work in assumption. Other prod- cost of not finding it. The process, Hawthorne ucts, however, were in a aim was to make it a mat- would not accept a lot tol- state of continuous pro- ter of indifference erance with a consumer's duction, so that division whether product of break- risk of 0.1; Bell Labs of the product into "lots" even quality was accepted would not accept a risk of was entirely arbitrary. As or rejected by the sam- 0.5. it turned out, sampling for pling plan, meaning a continuous production re- probability of 0.5. The AOQL concept quires a totally new sampling approach. In the case of defects that As the impasse was debat- would not be discovered ed, agreement was Lot tolerance percent de- in final test but would in- reached on a related mat- tective stead result in field fail- ter: as to work delivered by a stable process, what The idea of a limiting per- ures, there was no com- was of greatest impor- cent defective was readily promise. Such defects tance was quality over accepted, but the method were to be removed by "the long run." (Any really of establishing it was not. detailed inspection. bad lots would be detect- It was a disappointment The consumer's risk of 0.1 ed by virtually any sensi- to Hawthorne that "scien- ble sampling plan.) I recall tific" sampling provided pondering over that con- no help in establishing the

8 cept of quality "over the cially the concept of mini- his statement that he had long run" and then having mum inspection per lot. "gone into this quite care- a flash of illumination. It When I exhibited the fully, delving way back dawned on me that for AOQL concept to some of into our old records to any sampling plan there the Hawthorne managers, make very sure that my was an upper limit to the they recognized that here comments to you were en- percent of defects it would was a potential way out of tirely in order." At the accept. the impasse, and such same time I knew that I proved to be the case. had independently hit on If the production process those same two concepts. I were perfect and made no In later years I learned a don't recall the dates of defects, then clearly the few things about the need the "flashes of illumina- outgoing quality would for inventors to record the tion," but I have copies of be perfect. If the process dates of events. In 1944 I some of the charts I drew were extremely bad, then was working on my sec- at the time. They are dat- the outgoing quality ond book, Management of ed around September and would also be perfect Inspection and Quality Con- October of 1926. (See Fig- since every lot would be trol. The draft included a ures 1 and 2.) rejected by the sampling claim that I had invented plan and scrapped or the AOQL concept and To this day I don't know 100% inspected. (All sam- the associated concept of the dates of Bell Labs' in- pling plans assumed that minimum inspection per ventions of those same 100% inspection found all lot. When Dodge re- concepts, but based on defects present.) Since the viewed my draft he chal- Dodge's comments, I must outgoing quality was per- lenged that claim; he con- have finished in second fect no matter whether the tended that those concepts place. Some multiple dis- incoming quality were had been invented in Bell coveries must be in- perfect or extremely bad, Labs. I was taken aback, evitable when multiple it followed that in be- but I nevertheless revised minds are working on the tween there must be a the manuscript to show same subject matter. In maximum limit to the per- that the concepts had been any case, the matter now cent of defects present in developed jointly. seems far less important the outgoing product. We than it did to that young named this limit the aver- During my long associa- engineer 70 years ago. age outgoing quality limit tion with Dodge, I never (AOQL). knew him to make a false Process knowledge claim or even to exagger- I was gleeful about this ate. His objectivity was discovery, which led me absolute, as was his in- to other discoveries, espe- tegrity. I readily accepted

9 The Hawthorne managers ble processes the prevail- knew that many processes ing sampling plan was to had an inherent stability check the first and last that could be utilized dur- pieces and to accept the ing design of sampling lot if neither of these plans. For example, some pieces was defective. press operations are so stable that if the first and Hawthorne's contentions last pieces in the lot are that such practices should correct, it can be safely as- be recognized in the sam- sumed that (for some pling plans had little ef- types of dimensions) the fect on the Bell Labs mem- intermediate pieces are bers of the Committee on also correct. For such sta- Inspection Statistics and

10 Economy. They had It is interesting to note the first and second sam- learned that unsound em- how the focus of quality ples combined.) pirical practice abounded control has shifted during at Hawthorne, and they our century. In the first At the outset Bell Labs re- were wary of proposals half of the century the fo- sisted going to double that seemed to rest on em- cus was on inspection and sampling. They were slow piricism. In addition, they sampling plans. In the sec- to grasp the psychological strongly believed that in- ond half the focus was on values involved, but they formation about the lot quality planning and finally rose to the occa- should come solely from process capability. sion. In addition, it soon the sample rather than became evident that in from knowledge of Single, double, and multi- many cases the economics process stability. These ple sampling of double sampling were Bell Labs beliefs had a more attractive than those The original Bell Labs profound influence on the of single sampling. sampling proposals in- sampling plans ultimately volved single sampling; Multiple sampling (more evolved. The published the lot would have one than two samples) was plans did not take account and only one chance to be never considered serious- of the inherent stability of accepted by the sampling ly. Hawthorne regarded the processes but they did plan. This concept ran such plans as too complex include the variable of squarely contrary to a for shop use, and no one "process average": the his- longstanding and widely really pressed the issue. A torical percent defective used Hawthorne practice serious interest in multi- delivered by the process. of taking second samples, ple sampling would not The failure to take account especially when the first take place until two or of process stability added sample contained only three decades later. to the skepticism with one defect. "That might be Sampling for continuous which some inspection su- the only defect in the lot," processes was something pervisors greeted the pub- was the common argu- else. At one stage it lished sampling plans. In ment. Of course the shop seemed that such sam- the punch press example people were not aware pling would have to be cited earlier, the large ran- that by taking second done by arbitrary division dom samples demanded samples they were in- of the continuous flow by the published plan creasing the risks of ac- into lots. However, the seemed absurd (which cepting poor product. committee came up with they were). We can be (The committee quantified ingenious new concepts sure that in such cases the those risks; it standard- such as: published sampling plans ized them at about 0.15 for were simply ignored.

11  Inspect every unit of The published sampling In due course the commit- product until n consecu- tables were at first used at tee's trail was marked by tive units are good. Hawthorne and then published papers setting throughout Western's fac- out the concepts and  Once n consecutive tories. During World War mathematics behind the units are all good, initiate II, a modified version was tables. Chief among these sampling. prepared by Bell Labs for were Dodge's papers, each use by the U.S. Army. a masterpiece of clarity.vi  Thereafter inspect a That version was then fraction f of the product. published by the U.S. The control chart Continue sampling until a Government Printing defect is found. At that One of the major propos- Office as MIIL-STD-105A. point revert to detail in- als of Bell Labs' initiative In 1944, the tables were spection of n consecutive was that Hawthorne published for general units. adopt the control chart as use.v a means of detecting sig- Here again, duplicate in- The tables have been nificant changes in prod- ventions seem to have tak- widely used for decades; uct quality. en place — within Bell often they have been ref- Labs and by Bartky. Bell Labs' Inspection Engi- erenced in purchasing neering Department regu- contracts and in specifica- Publication of the sam- larly prepared numerous tions. They continue to be pling tables reports, including reports used. The concept of toler- on quality of Western's The committee did a good ating defects in the prod- manufactured product. job of thinking through uct, however, is now be- The accompanying charts the subject of sampling in- ing phased out by the showed performance spection. It evolved con- growing competition in month by month. Man- cepts and nomenclature quality. The approach to agers receiving those re- that have since become quality control is now ports faced the problem of embedded into the litera- shifting from emphasis on judging the causes of the ture of the subject. It also product inspection to the month-to-month varia- found or developed the new emphasis on continu- tions: which of them were mathematical formulas ous improvement in the due to chance (noise in the needed to produce sam- producing processes. The signal) and which were pling tables that could be philosophy that "to err is real (the result of some ac- applied to a wide variety human" is being chal- tual change in perfor- of practical situations fac- lenged by the new philos- mance). ing inspectors. ophy that "perfection is possible." Shewhart was a member of the technical staff in

12 Bell Labs. His duties in- my responsibilities to same hourly base cluded analyzing reports "sell" the chart to inspec- rates for the same on quality performance. tion supervisors. I rarely grade of work. Un- He came up with an ele- made a sale, and I was der the piecework gant and useful invention puzzled by the stated rea- system, however, — a perpetual test of sig- sons for rejection — they the former could nificance. seemed illogical and even increase their pay irrelevant. Today the real through higher He drew "limit lines" reasons seem clear. The productivity; there around the historical aver- inspection supervision was no such oppor- age performance. The saw no way in which con- tunity for inspec- lines were so calculated trol charts could help tors. that any point outside the solve their chief problems, lines had a low probabili- such as: Shewhart invented the ty of being due to chance. control chart on May 16, For example, the limit  The top priori- 1924. That was a "p" chart lines might be so spaced ties of shop fore- — a chart of percent de- that a point outside the men were to meet fective. He soon extended lines could happen by schedules and the concept to include chance only 5% of the maintain piece- control charts for average, time. The odds would work earnings. standard deviation, and then be 20-to-1 that a Quality was no still other measures. She- point just outside the lines higher than third whart was a keen advo- was not due to chance, on their priority cate for his invention, and and hence was likely due list. he hoped Hawthorne to a real change in the would find wide use for process. In this way, a  Many production pro- it. Nothing of the kind manager reviewing re- cesses continually spewed took place during the ports could ignore points out unacceptable levels of 1920s. within the lines and focus defects, yet there was in on those outside. place no effective provi- Hawthorne certainly had sion for process improve- many cases in which a It was a brilliant inven- ment. well-behaved process sud- tion; today myriads of denly ran amok. For these such charts are in use  The Inspection cases, however, there was worldwide. Nevertheless Branch faced a seri- little need for a sensitive the Inspection Branch ous internal morale detector of change: They managers made virtually problem. Produc- gave out piercing screams no use of the control chart. tion operators and that could not be ignored. At the time it was one of inspectors had the

13 It was a disappointment products. Bell Labs had spection of the to Shewhart that the con- made a thorough analysis samples: to be done trol chart was not widely of this process, and its by attributes, and adopted by Hawthorne. proposal was adopted to be checked for (That step would not with little revision, The conformance to en- come until two or three proposal: gineering require- decades later.) Yet She- ments and for qual- whart had little under-  Reaffirmed the ity of workman- standing of factory opera- concept of check in- ship. tions. During one Bell spection (later Labs visit to Hawthorne I called quality as-  Established a fourfold gave Shewhart a tour of surance) to be done standard classification of the factory. Evidently it by an agency inde- defects based on their seri- was his first visit to any pendent of the fac- ousness. factory. During the tour tory, the purposes  Adopted stan- Shewhart was trying to being first to pro- dard weights (de- reconcile the shop empiri- vide information to merits) for each se- cism with his philosophies managers on out- riousness class. and his concept of a "con- going quality as viewed by cus- stant system of chance  Adopted demerits per vii tomers, and second causes." Shop managers unit as the basic measure to provide added who listened to him soon of product quality. gave up; to them he was quality protection from another planet. They to the customers.  Provided guide- could understand him lines for action in  Divided only through an inter- the event of exces- Hawthorne's out- preter. Nevertheless he sive numbers of de- put into product came up with an inven- fects in the sam- groupings for the tion that many others ples. purposes of sam- would have loved to in- pling and report- vent. (I am one of them.)  Provided a standard ing. reporting format in terms Rating the quality of man- of demerits per unit, using  Established ufactured product Shewhart's control chart guidelines for tak- to identify the statistically ing samples so as to A third Bell Labs' propos- significant variations. al was to refine the "check be representative of inspection" process then the output. For elaboration, see mate- being used for rating the rial written by Dodge,viii  Established quality of Hawthorne's guidelines for in-

14 Dodge and M. N. Torrey,ix The exciting part of the the same subject matter and Juran.x job arose because the Bell might justify creating a Labs proposals posed nu- course to be taught in the Juran's role merous problems new to Hawthorne Evening Hawthorne, and these re- School. (Part of my moti- During the committee's quired ingenuity for solu- vation was that I needed activity, I found my new tion. Some of my contri- the money — I now had a job to be a mixture of butions were useful; they little family and could drudgery and excitement. even evoked positive make good use of the I drew endless charts — comments from managers. modest fee paid to operating characteristic They also brought me the evening school instruc- curves and others. (See job of training the senior tors.) I explored the idea Figure 3.) managers of the Inspec- with the authorities and I also spent endless hours tion Branch (division made a sale, I then computing sampling ta- chiefs and up) in probabil- worked up a text and bles with the aid of a man- ity theory, sampling, and gave the course a few ually operated Monroe other matters resulting times before turning it calculator It was soon re- from the activities of the over to another instructor. placed with a noisy pow- committee. I relished the The effect on Juran er-driven model that nev- opportunity of meeting at length with such influen- An innocent by-product of Bell Labs' initiative was its effect on my journey through life. It set in mo- tion a train of events that became a milestone on that journey, with luck playing a role at every turn:

 I was selected to attend Bartky's course on probability theory. ertheless took its time to tial men on subjects with grind out answers. (Today which I was completely at I was then selected to be- the electronic models ease. come an engineer in the silently give out instant new Inspection Statistical It also occurred to me that answers.) Department. the need for training in

15  The new department be- vivors.) My growing fami- came actively involved in ly was thereby spared the a high-visibility project risk of being plunged into led by senior managers. I the kind of poverty I had pulled my weight during endured as a child. that project. My duties as manager  I was assigned to train soon forced me to dele- the senior managers of the gate much of the detailed Inspection Branch in the work on statistical new subject matters, and methodology, so my ex- thereby was directly ex- pertise slowly rusted out. posed to them, at length. At the time I was unaware that while I was well-suit- Such was the train of ed for engineering duties, events that plucked me I was not well-suited for out of Hawthorne's grass managerial duties. In time blades and placed me on a that contrast would force fast track for promotion. me to change course, but By 1929, before my 25th that story must await a birthday, I had become a later volume of my mem- division chief, one of a oirs. dozen managers running the Inspection Branch — an organization of 5,000 people.

My new role as manager brought me prestige as well as welcome increases in salary. Even more important, it enabled me to remain employed at Hawthorne throughout the Great Depression, a time when the population of Hawthorne plummeted from about 40,000 people to about 7,000. (I was one of the youngest sur-

16 i Glenn E. Hayes and Harry G. Romig, Modern Quality Control (Encino, CA: BRUCE, a division of Benzinger, Bruce and Glencoe, Inc., 1977). ii Edward C. Molina, "Some Antecedents of Quality Control," Industrial Quality Control, July 1951, pp. 10-11. iii G. A. Campbell, "Probability Curves Showing Poisson's Exponential Summation," Bell System Technical Jour- nal, January 1923, Vol.2, pp.95-113. iv Frances Thorndike, "Applications of Poisson's Probability Summation)' Bell System Technical Journal, October 1926, Vol.5, pp.604-624. v Harold F Dodge and Harry G. Romig, Sampling Inspection Tables (New York, NY: John Wiley & Sons, Inc., 1944). vi Harold F. Dodge, "Notes on the Evolution of Acceptance Sampling Plans," Journal of Quality Technology, April 1969, July 1969, October 1969, January 1970. Following Dodge's death, the Journal of Quality Technology repub- lished in its July 1977 issue nine more articles written or co-written by Dodge. Many of these articles also tackle the subject of acceptance sampling plans. vii Walter A, Shewhart, Economic Control of Quality of Manufactured Product, 50th anniversary commemorative reissue (Milwaukee, WI: ASQ Quality Press, 1980), p. 130. According to Shewhart, "The unknown causes producing an event in accordance with the law of large numbers will be called a 'constant system of chance causes' because we assume that the objective probability that such a cause system will produce a given event is independent of time." viii Harold F. Dodge, "A Method of Rating Manufactured Product," Bell System Technical Journal, 1928, Vol.7, pp.350-368. ix Harold F. Dodge and M. N. Torrey, "A Check Inspection and Demerit Rating Plan." Journal of Quality Technolo- gy, July 1977. x J. M. Juran, editor, Juran's Quality Control Handbook, fourth edition (New York, NY: McGraw-Hill, Inc., 1988), pp. 9-22 to 9-29.