Τρίτη 17 Σεπτεμβρίου 2013

HISTORICAL EVOLUTION OF PURCHASING FUNCTION

Historical Evolution of the Purchasing Function
Interest in purchasing as a separate, important, and profit-contributing function of management has gained substantial momentum within the decade of the 1950s and up to the present. As one reviews the development of, and attention to, this function, he cannot help being impressed by the progress which has been made in the last few years.
Perhaps the recent, rapid advances in knowledge concerning the proper role of purchasing within the modern organization overshadow completely the early work and study devoted to this function. Some authors have indicated that such attention is solely a phenomenon of the last few decades.1 Even so, it is important to understand how the purchasing function has developed to the level and position it occupies today. A knowledge of what has happened in the past often will give one a keen insight into the problems of today and a better picture of what may occur in the future. A true comprehension of where we are today requires an understanding of where we have been and how, and in what areas, progress has been made. This understanding can be gained, at least in part, by a review of the available literature on purchasing to determine the concepts of early authors and to highlight the types of problems, and recommended action, presented in this literature. Such a review will show that the purchasing function was established as an important area of activity, and was being written about, much earlier than is commonly assumed.
This paper presents, chronologically, the early writings on the subject of purchasing. Magazine articles are reviewed through the year 1910, by which year such articles were appearing frequently. Books on purchasing are reviewed through 1928, in which year two books presenting an analytical, managerial approach to purchasing were published. From this review, it will be apparent that the purchasing function has historical roots which are much deeper than is often recognized by scholars and practitioners alike.
LITERATURE PRIOR TO 1900 One of the early classic books in management provides evidence that purchasing was established as a separate industrial function well over 100 years ago. Charles Babbage's book, On the Economy of Machinery and Manufactures (1832), referred to the purchasing function in two places. In discussing the organization of duties for a mining concern, one of the ten officers responsible for operating the mines was "a materials man [who] selects, purchases, receives and delivers all articles required."2 Later he mentioned, "It will have been found necessary to establish an accountant's department...and this department must be in communication with the agents who purchase the raw produce..." And in describing the importance of the division of labor he further noted that "a great reduction in the cost of the article which is brought to market" can be accomplished by utilizing "the precise amount of skill...necessary for the execution of each process...[and] throughout every stage...from that in which the raw material is procured, to that in which the finished produce is conveyed into the hands of the consumer ..."3 Certainly this early author recognized the basic importance of the purchasing function to the overall success of an organization. It also is interesting to note that he recognized a "materials man" who would have control of several functions, in addition to purchasing, which are embraced under the now-popular "materials management concept."
Another of the references made to purchasing before the turn of the century was in an 1870 trade magazine entitled "Purchasing Building Materials," which pointed out that through judicious purchasing a firm may be able to effect substantial savings in total production costs: After a bill of the necessary amount of lumber has been prepared, it will be found an economical practice to communicate with lumber dealers in various parts of the country, for the purpose of determining the price for the kinds of lumber required. In this way a shrewd and judicious builder or buyer may often save from twenty to fifty per cent in the price of his lumber. For example, if an elegant suburban villa were to be erected in the vicinity of New York City, and it were desirable to procure first-rate lumber at the lowest cash price, it would be well to communicate with dealers of lumber in Maine, Georgia, Virginia, or other locations from which the market is supplied with cheap and choice lumber. By addressing postmasters, editors of certain papers, or some other persons in those localities where large quantities of lumber are sawed, it will not be difficult to come into communication with reliable dealers, who would respond to a bill of lumber with satisfactory promptness.4
Although this article did not recognize or discuss the role of the purchasing agent, per se, it did focus on the idea that normally there are several purchasing alternatives, and the alert buyer would do well to consider not only his current vendors but also to investigate other potential vendors.
Interest in, recognition of, and writings specifically about the purchasing function in the area of railroad management preceded the same interest, recognition, and writing in the industrial field. This early interest in railroad management probably can be explained in part by the fact that railroads were among the largest business organizations in the latter half of the nineteenth century.
The first book found devoted exclusively to the purchasing and materials functions was written by Marshall M. Kirkman, Comptroller of the Chicago and Northwestern Railroad, and appeared in 1887. This book, The Handling of Railway Supplies--Their Purchase and Disposition, was concerned with the purchasing functions of railroad organizations.5
In introducing his book, Kirkman emphasized the importance of the purchasing function to the management of a railroad, and the lack of knowledge on the subject, as follows: The intelligence and fidelity exercised in the purchase, care and use of railway supplies, influences directly the cost of construction and operating, and affect, therefore, the reputations of officers and the profits of owners. Accounting officers are also interested in the subject, as it is connected with the details of their office. To many (perhaps the bulk of railway officers) the handling of railway supplies is an unknown quantity. The subject needs elucidation on many accounts.6
Kirkman felt that the employment of a purchasing agent was necessary for a railroad to perform the purchasing and materials functions efficiently, and he pointed out the difficulties which arose when the purchasing function was not centralized under one individual: The purchase of goods embodies many varied talents and experiences. The ability to buy advantageously depends largely upon the knowledge of men possessed by the purchaser and his skill in taking advantage of this knowledge. His value will, moreover, be dependent upon the discretion allowed him, and his judgment in exercising it. The position also requires technical skill. The person filling it must be experienced, otherwise his acts will not command the confidence or respect of his associates. His wisdom and fairness must be such that if he selects material contrary to the requisition made upon him, the person thus over-ruled will tacitly acquiesce therein and abide by the demonstration of its wisdom afterwards. Unless the operating officer has this respect for the purchaser, he will quite likely not use the article thus bought, or, if he does, will not give its advantages fair expression. The assistance that an experienced purchasing agent can extend to his associates is hardly to be estimated. His duties not only familiarize him with all new devices, but his observation enables him to point out those most likely to lessen expenses or add to the efficiency of a property.7
Kirkman also commented on the lack of attention often given to the selection of personnel to fill the position of purchasing agent, and he deplored this casual selection of persons for such an important position.
The great benefits that accrue to a railroad from a good purchasing agent are not so generally esteemed as they should be. Judging from the changes that occur, continuance in office is not thought to be a matter of especial importance...the place is too often looked upon as one that any man with ordinary intelligence can fill acceptably; a position at once agreeable and measurably lucrative, but not of great importance. No greater mistake could be made...To be able to buy its supplies at the lowest possible figure is of enormous value to a company, and a capable purchasing agent, it is probable, can save his employer a greater sum through the exercise of experience and intelligence, than any other officer of like grade.8
This work by Kirkman was the first complete book devoted solely to the purchasing and stores functions within an organization. Although the language appears stilted according to present-day usage standards, this was an amazing work, and it demonstrates that many of today's problems and approaches are remarkably similar to those of almost a century ago. The Kirkman book, plus other early railroad purchasing literature, is discussed in an earlier article in the Journal of Purchasing.9
Further indications of this early interest in the purchasing function by railroad organizations are provided by trade journals in the railroad field. In 1890, three issues of The Railroad Gazette contained articles which discussed the organization of the purchasing function and the duties of the purchasing agent, benefits of standardization, determination of amounts of materials and supplies to stock, and the disposition of surplus.10 The 1898 volume of this same journal contained no less than seven articles, or letters to the editor, on the subject of purchasing.
ARTICLES APPEARING
IN ENGINEERING PUBLICATIONS The following statement regarding the problem of buying tools that appeared in an 1892 issue of one of the engineering publications still might be applicable to some firms today: If a person, when he wants a machine tool, could wait six months for it, until he could examine all that are made of the kind he desires, he would then be able to select the best, if his judgment could be trusted to tell what is best after so prolonged a siege. Now most tools are selected quickly, because they are needed at once, and what appears to be the best is taken and set to work. Hence many poor tools are got where better ones could and would be taken if more time for investigation were had. There are of course establishments where the most suitable tools are selected and recommended by experts, and a few of these deserve all praise for candor and fairness, but many of them do not push forward the best tools, but advocate instead those most profitable to them as dealers, and if a buyer falls into the hands of such he may suffer for it. There seems to be a need of a more perfect means by which buyers can be made to know the comparative capacities and value of machine tools, so that when
they need such tools they may not be in any great doubt as to that which is nearest to their wants.11
The following two quotations from the early 1890s pointed out the importance of the buyer's position within an industrial firm and the possible misuse of this position: I don't know what the machine business is coming to. Generally when a big company is formed, a favorite or a relative of some member is made buyer, and the drummer who can talk the smoothest sells his goods. I tell you, sir, if there is one place more than another in a large concern that requires an honest, shrewd, experienced, practical man to make money in, it is the buyer's.12 The greatest fault practiced by impractical buyers is that of initial cheapness. To such a person oil is oil and coal is coal, irrespective of the quality or the source of the product. The cause of their being impractical buyers is that old cause, "talk is cheap," and the fluent person often gets a position he is qualified by neither nature or experience to fill.13
J. Slater Lewis, in his book which appeared near the turn of the century, provided some useful ideas on the organization of industrial establishments. In his "Staff Organization Diagram," he included the position of a "Suppliers Order Clerk" reporting to the "General Manager."14 The importance of proper attention to purchasing in the successful administration of a factory was shown by the following comments: The Manager, too, must know the best markets for purchasing materials, and be fully alive to all the tricks and dodges of each class of trader.15 The economical purchasing of stores is one of the most important factors in the successful administration of a manufacturing establishment ... Stores cannot, of course, be purchased advantageously without that particular shrewdness which is characteristic of a successful buyer; and no system of bookkeeping, however complete, can possibly dispense with that personal quality. But at that same time a complete record of prices and tenders received from time to time, and an orderly and methodical system of requisitioning ... are essential to the economical purchasing of stores.16 The lowest price is not by any means always the cheapest, and this remark applies not only to heavy goods, but to the lightest possible articles. For instance, a crank forging may be offered at such a low price that the buyer is tempted to give the order. He discovers, however, when the forging arrives, that in consequence of its rough and lumpy conditions he not only has to pay more for the forging per se in consequence of its unnecessary and abnormal weight, but that the extra labor involved in machining down to dimension is out of all proportion to the benefits accruing from the supposed bargain in first cost.17
Many of Lewis's ideas are still appropriate. The employment of specialists in purchasing did not, however, seem to be as highly developed as it is today, for Lewis pointed out: The Works Manager should be consulted in regard to the purchase of all material used in the works. In some instances the whole of the purchasing operations may with advantage be left to him ... It is, nevertheless, very important that the authority for purchasing be kept within strictly defined lines, and only exercised by officials who have been duly authorized, and who clearly understand what they are doing.18
LITERATURE, 1900-1910 Around the turn of the century articles specifically on the industrial purchasing function began appearing with some frequency in the engineering magazines. Hugo Diemer, a professor of engineering and a prolific contributor to various engineering publications, in 1900 wrote an article entitled "Functions and Organization of the Purchasing Department," in which he made several comments concerning the functions of this department, the qualifications personnel in purchasing positions should possess, and the paperwork to facilitate performance of the function.19 Regarding the qualifications necessary for performance of the purchasing job, and selection of buyers, Diemer commented: The successful accomplishment demands that the purchasing agent shall be a man who has a working knowledge of the particular industry for which he is to buy material ... To salesmen, the ignorant affable young clerk who has been promoted to the position of purchasing agent is a familiar type. He is frequently the cause of a salesman's prolonging his stay in a city several days, until finally he sees the man with whom he can have an intelligent conversation. It is quite evident that, where this is the case, the young man is a hindrance from an economic standpoint, since the additional cost of sales departments on account of prolonged stays is sufficient to increase materially the unnecessary expense connected with the placing of an article on the market. The securing of the most desirable delivery involves a knowledge of business methods and forms in which, unfortunately, purely technical or shop men have generally had but little training; and this fact is the excuse for the common practice of appointing, as purchasing agents, clerks who have had but little technical or shop knowledge.20
Of course the argument over technical versus business knowledge continues today. On the subject of price, Diemer commented that . . . much depends upon the shrewdness and tact of the purchasing agent. Courteous attention to salesmen is always desirable, and can be accorded without loss of time if nothing but strictly business conversation is indulged in.21
Diemer concluded his article with a statement of the desirable workload for a buyer, which by today's standards would be considered excessive if the buyer were doing a thorough, analytical job: All of the above systems can be successfully conducted by a purchasing agent with a competent stenographer as assistant, and he will need no other help if his orders do not exceed fifty or sixty a day.22
The importance of realistic material specifications in determining total production costs was the subject of several short articles which appeared around the turn of the century.23 These articles concentrated mainly on the engineer's responsibilities in specifying materials, and contained many of the suggestions found in today's literature on value analysis. The following quotation is typical: Good judgment and common sense are matters of primary importance in drawing up an engineering specification. The purpose of such a document may be said to be the attaining of a certain result for the least amount of money compatible with proper execution of the work involved; but curiously enough, the stipulation sometimes made in a specification, defeat that very object. An excellent illustration of this point was given recently by . . . [who] told of a specification for an engine received by his firm some time ago which was so overloaded with what might be called fads, or, at any rate, with what might quite well have been dispensed with, and consequently contained so many names of persons who were to supply particular pieces, that the price was enormously increased.24
In 1905, in introducing an article on purchasing which previewed several to follow, the editors of The Engineering Magazine said: The Engineering Magazine has been the source of much of the existent literature dealing with the organized study and management of two of the great elements in the economy of manufacturing--labor and general expense. We believe it will be of interest to supplement these with a further study of the application of scientific business methods not only to the internal handling, but also to the supply, of the third prime factor in manufacturing--materials-- The Editors.25
Although largely concerned with the forms and records used to facilitate purchases, this article took a broad view of the purchasing function and the responsibilities and work of the buyer. It is significant that it recognized clearly the need for attention to the materials functions within an organization and that this attention followed similar emphasis on labor and general expense. Appropriate quotations on the responsibilities and contributions of the buyer follow: Assuming that the works superintendent is responsible for the consumption of materials per unit of output, while the business manager is accountable for the cost thereof, there appears a necessity for a third element in industrial organization having jurisdiction over the prices paid for materials. This is the function, as usually understood, of the buyer. He is technically differentiated from both superintendent and manager, bearing nor formal responsibility regarding the consumption of materials either absolute or in proportion to production; nor, usually, regarding the cost per unit of production, so long as the prices paid are low. This strict limitation of the accountability of the purchasing department is, and should be, never adhered to. Properly considered, buying has other relations intimately associating it with considerations of production-intensity and profit, the nature of these relations, and their utility depending upon the kind of industry and its mode of organization.26
Ennis also referred to the need for price knowledge and determination of price by the buyer as follows: . . .there should be intelligently designed records showing the variations in prices of the principal supplies purchased, accompanied by thorough analysis showing the reasons for the variations. Any opportunity for comparisons of prices with those paid for the same materials by others should be taken advantage of, and the facts recorded. To be most familiar with the markets, the buyer should be supplied not only with his own trade papers, catalogues and other publications, but also with the trade papers covering the markets he most often enters.27
Ennis also referred to the need for commodity specialization within the purchasing department and recommended: Where the organization is large, so that the personal attention of the buyer cannot be given to the details of all purchases, the materials should be grouped in general classes and each class handled by one subordinate. Special knowledge is just as essential in purchasing as in manufacturing.28
He also commented on the organizational centralization of the purchasing function in large, multi-divisional companies. In the recent "integrated" mode of organization of many industries, involving the combination under one direction of a number of geographically separated plants, it has seemed wise to form a new basis for buying, consisting in the establishment of a central purchasing department, which takes direct charge of the buying of the larger and repetitional items, supervising at the same time the local purchasing of smaller items at the various plants . . .29
The lack of attention given by some managements to purchasing was pointed up by another 1905 article. Before discussing the necessity for system and records in purchasing, the author commented that the purchasing department . . . is usually the last to pass from under the personal control of the proprietor of the firm. There are many concerns that have found it necessary to secure experienced men from outside for their manufacturing and sales departments, and yet are satisfied to run their purchasing department in the same old way . . . These things show that the mass of business houses have not yet discovered the fact that their purchasing department needs the application of modern methods of business economy.30
In 1905 the second book specifically devoted to the purchasing function--and the first book on other than railroad purchasing--was published, as one of the volumes in a home study series. Book on Buying contained 18 chapters, each by a different individual.31 The first part of the book (pp. 1-80) was concerned with the "principles" of buying, while the second part (pp. 81-216) consisted of 11 chapters describing the forms and procedures used in various company purchasing systems. This book was introduced by the statement that too little attention had been paid to the purchasing function in the past: But little attention has, up to this time, been paid to the science of buying; this too, in the face of the fact that there is no department that contributes any more to the success of a business than that concerned with the purchase of material, stock, and supplies. When it is considered, that buying requires not only keen, shrewd, business judgment, but also a vast amount of technical knowledge compactly arranged, it is evident that the systematization of the department of purchasing, too, is worthy of careful research, study, and treatment.32
Book on Buying makes several comments on the effects of the performance of the purchasing function on the success of a business, two of which follow: The secret of the great importance of good buying lies here: The buyer looks always to the profits of the concern which he represents . . . Here is the first place at which profits may be made. Here is the first place in business organization that ability may be shown.33 In every line of business dependent upon selling, the importance of good buying is adequately recognized. While there is a tendency on the part of the salesman to define his work as that of the man "who keeps the smoke coming out of the factory chimneys," and to always carry the idea that he is on the end that brings in the money, yet the relative importance of selling and buying is no more clearly shown than by the fact that incompetence or inability on the part of the salesman may bankrupt his firm; on the part of the buyer it is sure to.34
In discussing the knowledge and skills required to do an adequate purchasing job, Book on Buying gave much emphasis to what it called "knowledge of the market": Nor is knowledge of prices more than a beginning of knowledge of market. The mere fact that a certain price rules is no sure guide. The shrewd buyer must look beyond the mere price and must reach into the causes which have made that price, and those that are material in its remaining at that point, or in causing its fluctuation up or down.35
The concluding chapter introduced the possibility of combining several of the materials functions under the responsibility of the purchasing agent to gain the benefits of coordination, which is similar to the materials management concept so widely discussed today: It is now the common practice in by far the larger percentage of manufacturers and works to keep separate the purchasing agent's duties as follows:
(1) Purchasing of raw material.
(2) Storing of raw material.
(3) Stocking of finished components. Where conditions are as have been treated before in this article, it will be found that by combining in one department these various functions, that not only will factory organization be furthered but the resulting benefits of good factory organization will accrue.36
Many other articles appeared after 1905 in the various engineering journals. The Engineering Magazine (which in November, 1916 was retitled Industrial Management) appears to have carried the majority of such articles.37 These articles primarily were concerned with the forms and records which made up the system used in purchasing.
Cassier's Magazine first published an article specifically on purchasing in 1908. This described the effect in one company of changing the responsibility for supervision of the purchasing function from clerical to engineering personnel and concluded: The purchasing agent alone determined where the orders were to be placed for all goods, which discretion he exercised to the best of his ability, having absolutely no friends to please in the trade, and being under no obligations whatever to favor anyone more than another. Nor did the foremen or heads of departments undertake to specify when making out their requisitions whose make or brand of goods should be used.38
In 1908 The Engineering Magazine began a series of articles on the organization for production of manufacturing companies. From these articles the organizational level which the purchasing function had achieved in some companies soon after the turn of the century readily can be seen. The first such article concerned the Lynn, Massachusetts works of General Electric and contained an organization chart showing the purchasing agent on a level with the mechanical superintendent, superintendent of production, and factory accountant. All these positions reported to the general manager, who in turned reported to a vice-president.
Also in 1908, the organization of the Westinghouse Electric and Manufacturing Company was discussed:
Under the plan of organization of the Westinghouse Electric and Manufacturing Company there are six departments directly concerned in production, viz.:1. The Correspondence Department, 2. The Engineering Department, 3. The Purchasing Department,4. The Manufacturing Department,5. The Raw and Finished Material Stores,6. The Shipping Department. The heads of the first three report directly to one of the vice-presidents while the last three are in charge of the manager of works who reports also to a vice-president.
BOOKS ON PURCHASING, 1911-1921
The third book devoted to the purchasing and materials functions, The Supply Department (1911), primarily concerned railroad purchasing and materials practices. The author, H.C. Pearce, General Storekeeper of the Southern Pacific Company, stated that supply departments were established and maintained on some railroads
...as long as 25 years; notably the Chicago & North Western; the Chicago, Milwaukee and St. Paul; the Union Pacific; the Burlington; and the Great Northern. The last ten years have brought great consolidation, new methods and economics, particularly as to the system of buying from manufacturers on specifications. This necessitated a more thorough and complete supply organization, and today, with one exception, there is not a system of any importance that has not a supply department, the business of which is to provide, distribute and account for all materials.
Pearce advocated a type of materials management organization in which there was an "officer in charge of materials and supplies," to which a "Purchasing Agent," "Fuel Agent," "General Storekeeper," and "Engineer of Tests" reported, and said:
On properties which the amount of materials used does not warrant an organization of this kind there should be a supply agent who would be responsible for both the buying and distribution. On larger systems, however, unquestionably the proper organization is an officer in charge of both purchases and distribution, with a sub-head to do the buying and another to maintain the stock and have charge of the distribution.
Three books on the purchasing and materials functions appeared in 1915, indicating a growing interest in the subject. Materials and Supplies was in three sections: the first on "Purchasing Methods," the second on "Setting Up Material Standards," and the third on "Storekeeping." Each section contained chapters written by several different individuals.
Purchasing was written by C.S. Rindsfoos, President of the United States Purchasing Corporation, a buying company which performed the purchasing functions for other companies for a fee. The author, understandably, attempted to promote the idea of buying companies (although evidently with little success) and stated:
The author believes there are many reasons why the ideal purchasing department of the not far distant future will be in the form of a separate company. In fact, one or two such companies are already organized and in successful operation--successful in the saving they effect for their clients no less than in the profits they earn.
This book gave little attention to the forms and procedures of purchasing; instead it discussed subjects such as determination of price, service, and terms. Chapter seven, entitled "strategy," contained some interesting suggestions which would fit well into some of the literature on negotiation--a subject currently receiving much attention:
The strategist is a student of human nature. The application of strategy in buying, as well as in selling, involves a knowledge of human nature and the ability to portray. The buyer must study the man with whom he deals, seek out his weaknesses, discern what is in his mind, learn the policies of the house he represents and act or portray his own part accordingly. One man can be flattered; another can be bullied. One man can be won by an appeal to his sense of fairness; whereas another who is always looking for an opportunity to get the better of the buyer can be made to think he is succeeding and so be made to fall into his own trap. It is no less essential to know the failings of the seller than it is to conceal one's own desires, weaknesses and thoughts.
The third of the books to appear in 1915 was a brief, general approach to the subject written by H.B.Twyford, Purchasing Agent of the Otis Elevator Company. Chapters were included on "Ethics of Buying," "Organization of the Department," "Obtaining and Tabulating Proper Records," plus chapters on purchasing problems of different types of industries.
As had several other authors, Twyford commented on the lack of knowledge available on the subject of purchasing, stating:
Constructive thinking in its application to the production department has been elaborated on in many volumes, and in the technology journals and periodicals. The literature on the art of salesmanship is voluminous and highly scientific. The problems connected with accounting methods have been analyzed and discussed exhaustively. The intricacies of finance have been sifted and examined, and placed before students of the subject in an interesting and attractive form. This is in contradistinction to the literature devoted to the philosophy and art of buying, which is neither extensive nor exhaustive, although it is a subject of equal importance and is an attractive and alluring study.
Twyford placed great emphasis on the necessity for a purchasing agent to systematically collect and study data relating to the materials he was buying and the vendors with whom he dealt, as the following quotation illustrates:
It has been stated that there is no such thing as scientific buying, but that good buying is the result of intuitively knowing when and how to do it, which, with a combination of luck, makes a successful buyer. It can be admitted that with this equipment a successful gambler may be evolved, but intuition is too vague a qualification for the purchasing agent of any establishment, large or small. There is a great deal more necessary in the makeup of any man who has charge of such work as is being considered here. He must have good judgment, be well balanced, shrewd, sagacious, and well fortified with the knowledge which he can scientifically accumulate; this, broadened and improved by a close study of local and national conditions, will make a purchasing agent a valuable asset to any concern.
For some reason no books on purchasing appeared for the next five years. Although many authors indicate that it was during the war years of 1914-1918 that the purchasing function first received considerable recognition, no books on purchasing were published from 1916 to 1920.
BOOKS ON PURCHASING, 1921-1928
In 1921 a second book appeared by H.B. Twyford.(51) This book was very similar to his earlier, 1915 book.
In the year 1922, no less than six books appeared which were either entirely devoted to purchasing or had major parts devoted to the purchasing function. Some of the statements in these books are of interest in showing the prevailing attitude toward purchasing and the purchasing agent.
Albert E. Bull's book attempted to cover the work of the buyer in all lines: retail, wholesale, manufacturing, import and export.(52) His comments on the position of the buyer, relative to the salesman, are most interesting:
Buying, on the whole, is rarely as important as selling. Salesmanship in which is involved the opening of new markets, the extension of trade, the actual creation of a commercial concern, demands greater ingenuity, a bolder course of action, a finer imagination and a wider power of resource than buying can ever do.
A salesman must be hopeful and creative. He should possess robust health and have plenty of vital forces to burn up. A buyer can be morose and ill and cross-grained and despairing, without doing himself or his cause much harm.(53)
The only purchasing book authored by a woman was published in 1922.(54) Helen Hysell's comments on the increasing recognition of the purchasing manager within the organization structure, and also her material on analysis of individuals, are of interest.
BUSINESS CYCLES AND PLANNING AHEAD--The purchasing agent should be in the "crow's nest" or "lookout" of the business craft equally, if not more often, than the sales director. The sales department may figure out its plans for a year ahead, but, without the purchasing agent's cooperation in obtaining the raw materials to manufacture, or the finished materials for them to resell, on terms at a price that will meet competition at the time of the sale, the sales department, as well as the financial department, will be greatly handicapped and the aim of all departments--profit--will be that much lessened if not entirely consumed.(55)
She also gave advice on how to analyze character and disposition of salesmen:
For example, the broad, high, square-shaped forehead indicates analytical power, intelligence, perseverance, and severity. The more it tends toward rounded, and cornerless outlines, the more flexibility of character does it indicate. The retreating forehead indicates imagination, feeling, wit and keen perception. The projecting forehead is a sign of weakness of will.
The eyes indicate the feeling rather than the intellect, though there are a few rules that are more or less reliable.
The chin and lips are watched not only for construction, but also for expression. Thin lips usually indicate industry and order, etc. If the lips are drawn at the corners they show a weak or pessimistic disposition. Large, well-defined lips show energy and vitality. Lips, however large, if well formed and well closed, indicate power, ability, energy and good sense.(56)
Salesmen, as a rule, are reluctant to offer to shake hands with the purchasing executive as they have learned, through experience, that many purchasers dislike the practice. It is well, however, for the purchasing director to offer his hand to the salesman. This gives an additional opportunity for judging the type of man with whom he is about to talk.(57)
John C. Dinsmore, who at the time was Purchasing Agent at the University of Chicago, wrote a book on purchasing which treated briefly the procedures for performing the purchasing function and had several chapters devoted to the purchase of specific types of commodities.(58)
Madison Cartmell, in a book primarily devoted to storekeeping and concentrating on procedures,(59) commented on the growing importance being accorded to performance of the purchasing function, but he also recognized that not all firms considered the purchasing function as requiring specialized personnel:
The purchasing department is a comparatively new factor in business organization. Its general adoption reflects changing conditions in purchasing and an increasing realization of the important part played by good buying in the success of any business enterprise. There are many large concerns, however, which persist in the old method of departmental buying.(60)
The other two books to appear in 1922 primarily emphasized the stores
function rather than the purchasing function, although devoting some space to the performance of purchasing.61
In 1924 a book by H.D. Murphy appeared, which was a very brief treatment of the duties of the purchasing agent.62 In 1927 William N. Mitchell authored a book which provided a general discussion of all phases of activity of an industrial purchasing department.63
Two books appeared in 1928. One, Principles of Scientific Purchasing, was written by Norman F. Harriman, who was employed in purchasing with the Union Pacific Railroad.64 Relative to the importance of the purchasing function and the progress which had been made up to that time, Harriman said:
The science of buying is recognized more clearly in its proper perspective today than ever before. Increasing consideration is being given not only to the first cost but also to the longer range factors of fitness, interchangeability, renewals, replacements, general maintenance, wearing qualities, and cost per unit of utility. The tendency to buy at so much per unit of quality or utility, instead of per unit of quantity, is one that will increase. The idea is fundamentally and economically sound.65
Harriman's book recommended the scientific, systematic collection of data, by specialists, as a basis for purchasing decisions.66 Specifically, he noted and recommended use of individuals called "Purchase Engineers" to aid the buyers in investigating potential areas of cost reduction.
Another book which also appeared in 1928, Scientific Purchasing, was authored by Edward Tisdale Gushee and Lionel Frank Boffey.67 These authors also approached the subject of purchasing from an analytical point of view, emphasizing the importance of systematic data collection by specialists. They referred to an "Economics Division" within the Purchasing Department and stated:
The economics division is an extremely important part of the purchasing organization. Broadly, the function of this department is to maintain all records relating to the prices of products, to study materials and markets, to analyze the prices paid for commodities and equipment, and generally to point the way to savings through more intelligent specifications and supervision of sources of supply. This division or its equivalent is essential for every purchasing department which expects to make major savings. Economy in purchasing is not a matter of selecting the lowest of a number of bids, but of knowing that the material bought is adopted for requirements, efficiently produced, and bought at a price which represents a fair profit to the seller.68
The authors also emphasized proper timing of purchases based on analysis of data and stated:
There are some purchasing agents who believe, or profess to believe, that to buy successfully demands a sixth sense--a sort of intuition or "hunch" as to the trend of general business and the tendency of specific markets.
That belief is utter nonsense. As a matter of fact, the purchasing agent who claims that he follows a "hunch" in a particular transaction will find, on self-analysis, that his action is really based on what he has read or heard."69
Market studies, economic analyses, graphic charts accurately and regularly revised, established policies of purchasing to take the utmost advantage of prevailing conditions--these are facilities which are essential to enable the purchasing agent to time his buying most effectively, providing he has the wisdom to interpret business conditions and the courage to act in conformity with the interpretation.70
Judged by present-day standards both the Harriman and the Gushee and Boffey books were amazing pieces of work. Many of their comments are as relevant today as when they were made. Also, these books were the first to place major emphasis on the analytical aspects of purchasing. Yet, it does not appear that either book had any immediate impact on purchasing practice--this probably was due to the timing of their publication (the beginning of "The Great Depression") rather than the merits of the books themselves.
CONCLUSIONS
This research into purchasing literature up to 1928 established that the purchasing function has a rich historical background. Persons were interested in, and writing about, purchasing well before the turn of the century. By 1910 journal articles on purchasing were appearing quite frequently. In the decade of 1911-1921 several books on the subject were written, and in 1928 two books appeared which emphasized the analytical basis of purchasing. Review of these writings shows that many of the problems currently being discussed are not new, but instead they were recognized and discussed many years ago.
These data refute the commonly held and often stated beliefs that interest in purchasing is solely a product of this century and primarily of the events surrounding World War I. Purchasing is a much older and better recognized function than commonly thought. Further research to put the development of ideas about purchasing into their proper historical perspective is needed.
REFERENCES: 1. For example, "Procurement has only recently become an important and correlated function of management. It was unusual indeed, prior to World War I, for purchasing to be ranked as an independent activity ... World War II really established procurement as a major function of management." Henry G. Hodges, Procurement: The Modern Science of Purchasing (New York: Harper and Brothers, 1961), p. 1. 2. Charles Babbage, On the Economy of Machinery and Manufactures (London: Charles Knight, Second edition, 1832), p. 202. 3. Ibid., p. 216. 4. "Purchasing Building Materials," The Manufacturer and Builder, Vol XI (February, 1870), p. 57. 5. Marshall M. Kirkman, The Handling of Railway Supplies--Their Purchase and Disposition (Chicago: Chas. N. Trivess, 1887), 223 pages. 6. Ibid., Preface. 7. Ibid., p. 40. 8. Ibid., p. 42. 9. Harold E. Fearon, "The Purchasing Function Within Nineteenth Century Railroad Organizations," Journal of Purchasing, Vol. 1 (August, 1965), pp. 18-30. 10. "Purchasing and Care of Supplies," The Railroad Gazette, Vol. XII (February 14, February 21, and March 14, 1890), pp. 105-06, 126-27, 172-73. 11. "Machine Shop Notes," The Engineering Magazine, Vol. VI (December, 1892), p. 477. 12. Ibid., p. 478. 13. "Machine Shop Practice," The Engineering Magazine, Vol. VI (October, 1893), p. 114. 14. J. Slater Lewis, The Commercial Organization of Factories (London: E. & F.N. Spon, 1896), pp. 474-75. 15. Ibid., p. 8. 16. Ibid., p. 54. 17. Ibid., p. 108. 18. Ibid., p. 132. 19. Hugo Diemer, "Functions and Organization of the Purchasing Department," The Engineering Magazine, Vol. XVIII (March, 1900), pp. 833-36. 20. Ibid., p. 833. 21. Ibid., p. 836. 22. Ibid. 23. See, for example, "Current Topics," Cassier's Magazine, Vol. XXIV (June, 1903), p. 176; and Vol. XXVI (September, 1904), p. 507. 24. "Current Topics," Cassier's Magazine, Vol. XIV (April, 1901), p. 508. 25. William D. Ennis, "The Relation of Purchasing to Production," The Engineering Magazine, Vol. XXIX (July, 1905), p. 519. 26. Ibid. 27. Ibid., p. 528. 28. Ibid. 29. Ibid., p. 539. 30. Harold A. Wright, "The Fine Art of Buying," The World's Work, Vol. X (July, 1905), p. 6439. 31. H.T. Kett, et. al., Book on Buying, The Business Man's Library, Vol. V (New York: The System Company, 1905), 216 pages. 32. Ibid., p. 3. 33. Ibid., p. 23. 34. Ibid., p. 32. 35. Ibid., p. 12. 36. Ibid., p. 195. 37. The Engineering Magazine contained the following articles: J. Cecil Nuckols, "A Complete System for the Purchasing Department," Vol. XXXV (April, 1908), pp. 26-32; A.C. Ward, "The Purchasing Department of a Manufacturing Organization," Vol. XLVI (December, 1913), pp. 349-55; Herbert R. White, "Records for the Purchasing and Supply Department," Vol. XLVI (January, 1914), pp. 571-76; William H. Morse, "The Purchasing Agent and High Class Product," Vol. XLIX (June, 1915), pp. 333-35; and H.B. Twyford, "Fundamental Requisites in Purchasing," Vol. LLI (March, 1917), pp. 800-05. 38. James M. Cremer, "The Engineer as a Purchasing Agent," Cassier's Magazine, Vol. XXXIV (August, 1908), p. 332. 39. George F. Stratton, "The Management of Production in a Great Factory: Division of Responsibility and Authority in the General Electric Company's Shops," The Engineering Magazine, Vol. XXXIV (January, 1908), p. 572. 40. H.M. Wharton, "The Production System of the Westinghouse Electric and Manufacturing Company," The Engineering Magazine, Vol. XXXIV (March, 1908), p. 891. 41. H.C. Pearce, The Supply Department (New York: Railway Age Gazette, 1911), 112 pages. 42. Ibid., p. 2. 43. Ibid., p. 108. 44. Materials and Supplies, The Factory Management Series (Chicago: A.W. Shaw Company, 1915), 216 pages. 45. C.S. Rindsfoos, Purchasing (New York: McGraw-Hill Book Company, Inc., 1915), 165 pages. 46. Ibid., p. 104. 47. Ibid., p. 69. 48. H.B. Twyford, Purchasing--Its Economic Aspect and Proper Method (New York: D. Van Nostrand Company, 1915), 236 pages. 49. Ibid., p. 17. 50. Ibid., p. 26. 51. H.B. Twyford, Purchasing and Storing, Factory Management Course, Vol. IV (New York: Industrial Extension Institute, 1921), 435 pages. 52. Albert E. Bull, Buying Goods: The Commercial Buyer and His Work (London: Sir Isaac Pitman & Sons, Ltd., 1922), 96 pages. 53. Ibid., p. 1. 54. Helen Hysell, The Science of Purchasing (New York: D. Appleton and Company, 1922), 261 pages. 55. Ibid., p. 102. 56. Ibid., p. 44. 57. Ibid., p. 50. 58. John C. Dinsmore, Purchasing: Principles and Practices (Englewood Cliffs, New Jersey: Prentice-Hall, Inc., 1922), 295 pages. 59. Madison Cartmell, Stores and Material Control, Including Procurement by Purchase (New York: Ronald Press Co., 1922), 459 pages. 60. Ibid., p. 257. 61. Henry H. Farquhar, Factory Storekeeping: The Control and Storage of Materials (New York: McGraw-Hill Book Company, Inc., 1922), 182 pages; Alexander Hamilton Church, The Making of an Executive, "Purchasing and Storekeeping," Book II, Part 4 (Scranton, Pennsylvania: International Textbook Company, 1922), pp. 1-55. 62. Harry Duncan Murphy, The Fundamental Principles of Purchasing (New York: Purchasing Agent Company, Inc., 1924), 83 pages. 63. William Norman Mitchell, Purchasing (New York: Ronald Press Company, 1927), 385 pages. 64. Norman F. Harriman, Principles of Scientific Purchasing (New York: McGraw-Hill Book Company, Inc., 1928), 301 pages. 65. Ibid., p. 21. 66. Ibid., pp. 113, 122-23, 229-30. 67. Edward Tisdale Gushee and Lionel Frank Boffey, Scientific Purchasing (New York: McGraw-Hill Book Company, Inc., 1928), 196 pages. 68. Ibid., p. 59. 69. Ibid., p. 99. 70. Ibid., p. 104.

Τετάρτη 11 Σεπτεμβρίου 2013

INVENTORY MANAGEMENT - ECONOMICAL ORDER QUANTITY


Inventory Management

§  Introduction
§  Economic Order Quantity (EOQ) Model
§  Economic Production Quantity Model
§  Quantity Discounts Model
§  Reorder Point (Q System)
§  Shortages and Service Levels
§  Single Period Model


Definition of Independent Demand Inventory


Independent demand inventory consists of items for which demand is influenced by market conditions and is not related to production decisions for any other item held in stock.

Contrast this with dependent demand inventory, consisting of items required as components or inputs to a product or service.  We will talk about managing dependent demand inventory in manufacturing using a material requirements planning (MRP) system.


Types of Inventory



·      Cycle inventory


·      Safety stock


·      Anticipation inventory


·      Pipeline inventory



Managing Independent Demand Inventory


Managing independent demand inventory involves answering two questions:

·      How much to order?

·      When to order?



Five Assumptions of EOQ


·      Demand is known and constant

·      Whole lots

·      Only two relevant costs

·      Item independence

·      Certainty in lead time and supply

Total Annual Relevant Cost


a.  Annual holding cost

       Annual holding cost =

b.  Annual ordering cost

       Annual ordering cost =

c.  Total annual relevant cost:

Derivation of Economic Order Quantity (EOQ) and Time Between Orders (TBO)

Total annual relevant cost:  C =
Take the first derivative of cost with respect to quality: 

Setting  and solving for Q: 

Time between orders: 


Overland Motors Example

Overland Motors uses 25,000 gear assemblies each year (i.e. 52 weeks) and purchases them at $3.40 per unit.  It costs $50 to process and receive each order, and it costs $1.10 to hold one unit in inventory for a whole year.  Assume demand is constant.

Ralph U. Reddie has been ordering 1,000 gear assemblies at a time, but can adjust his order quantity if it will lower costs.

a.     What is the annual cost of the current policy of using a 1,000-unit lot size?






b.    What is the order quantity that minimizes cost?






c.     What is the time between orders for the quantity in part b?







d.    If the lead time is two weeks, what is the reorder point, R?

Economic Production Quantity


1.  Maximum Cycle Inventory

  

2.  Total cost = Annual holding cost + Annual ordering or setup cost

  

3.  Economic Production Lot Size (ELS)

      

Economic Production Quantity Example

A domestic automobile manufacturer schedules 12 two-person teams to assemble 4.6 liter DOHC V-8 engines per work day.  Each team can assemble five engines per day.  The automobile final assembly line creates an annual demand for the DOHC engine at 10,080 units per year.  The engine and automobile assembly plants operate six days per week, 48 weeks per year.  The engine assembly line also produces SOHC V-8 engines.  The cost to switch the production line from one type of engine to the other is $100,000.  It costs $2,000 to store one DOHC V-8 for one year.

a.    What is the economic lot size?



b.   How long is the production run?



c.    What is the average quantity in inventory?



d.   What are the total annual relevant costs?



Quantity Discounts



In the case of quantity discounts (price incentives to purchase large quantities), the price, P, is relevant to the calculation of total annual cost (since the price is no longer fixed).


Total cost = Annual holding cost + Annual ordering cost + Annual cost of materials





Quantity Discounts
Two-Step Procedure



Step 1:
Beginning with lowest price, calculate the EOQ for each price level until a feasible EOQ is found.  It is feasible if it lies in the range corresponding to its price.

Step 2:
If the first feasible EOQ found is for the lowest price level, this quantity is best.  Otherwise, calculate the total cost for the first feasible EOQ and for the larger price break quantity at each lower price level.  The quantity with the lowest total cost is optimal.

Quantity Discounts Example


Order Quantity
Price Per Unit
0-99
$50
100 or more
$45

If the ordering cost is $16 per order, annual holding cost is 20 percent of the per unit purchase price, and annual demand is 1,800 items, what is the best order quantity?

Step 1.                =

                           =


Step 2.                  =

                           =




Reorder Point (Q System)


A continuous review (Q) system tracks the remaining inventory of an item each time a withdrawal is made, to determine if it is time to reorder.

Decision rule:  Whenever a withdrawal brings the inventory down to the reorder point (R), place an order for Q (fixed) units.


Reorder Point

Demand pattern
Lead time for ordering
ROP
Known and constant
None
ROP = 0
Known and constant
Known and constant
ROP =
Variable, normally distributed,  known
Known and constant
ROP =
Variable, normally distributed,  known
Known and constant
ROP =
Known and constant
Variable, normally distributed,  known
ROP =
Uncertain, discrete probability distribution
unknown
Determine ROP for a given service level based on the cumulative probabilities of demand during lead time. 

Shortage and Service Levels

Expected Shortage per order cycle:
E (n) = E (z)

E(z) = standardization parameter obtained from Table 11.3.

 = standard deviation of lead time demand

Expected shortage per year:
E (N) = E (n)

Annual Service Level:


Q System Example

You are reviewing the company’s current inventory policies for its continuous review system (Q system), and began by checking out the current policies for a sample of items.  The characteristics of one item are:
·       Average demand = 10 units/wk (assume 52 weeks per year)
·       Ordering and setup cost (S) = $45/order
·       Holding cost (H) = $12/unit/year
·       Average lead time (L) = 3 weeks
·       Standard deviation of demand during lead time = 17 units
·       Service-level = 70%

a)     What is the EOQ for this item?


b)    What is the desired safety stock?


c)     What is the desired reorder point R?


d)    What is the decision rule for replenishing inventory?


e)  What is the expected shortage per year?



If instead of the above situation, suppose the lead time is known and constant at 3 weeks and the standard deviation of demand during lead time is unknown.  However, we do know the standard deviation of weekly demand to be 8 units.  How do your answers change?


Cycle-Service Level with Discrete Distribution

·       Set R so that the probabilities of demand at or below its level total the desired cycle-service level.
·       To find safety stock, subtract expected demand during lead time from R.

Application:

The demand during lead time distribution is shown below, along with possible R values and their corresponding cycle-service levels.

Demand
Level

Probability

R
Cycle-Service
Level (%)
0
0.30
0

50
0.20
50

100
0.20
100

150
0.15
150

200
0.10
200

250
0.05
250



a.     What reorder point R would result in a 95% cycle-service level?

b.    How much safety stock is provided with this policy?











Single Period (Newsvendor) Model

Used to handle ordering of perishables and items that have a limited useful life.

shortage costs = unrealized profit per unit
excess costs = the unit cost less the salvage value

1.  Calculate the shortage and excess costs:

2.  Calculate the service level (SL), which is the probability that demand will not exceed the stocking level:

SL =

3.  Determine the optimal stocking level, , using the service level and demand distribution information.

 = Mean demand + zSL*sdemand