M
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
GO TO M, Mak Mad, Mai, Man, Mar, Mas, Mat, Mb, Mc Me, Mea, Mem, Met, Mh, Mil, Min, Mis, Min, Mis, Ml, Mm, Mo, Mod, Mon, Mos, Mp, Mr, Mt Mu, Mv last entry
M&A: City talk for mergers and acquisitions.
M&S: Marks & Spenser, a UK retail chain specialising in clothing and food, or Modelling & Simulation.
Ma Bell: synonymous with AT & T, qv.
M-Day Calendar: See Shop Calendar.
Machine Capability: Machine capability is calculated in the same way as process capability, but is intended to represent the capability of the machine in isolation, thus excluding such sources of variation as human operation, incoming material differences and changes in the environment (eg temperature). The data to calculate machine capability are thus gathered over as short a period as possible (compare process capability, where the data are gathered over, say, a month, so as to include all sources of variation).
MAD: Mean Absolute Deviation. A short-cut technique popularised in the 1950s because of the inability of computers in those days to calculate square roots, as required in the calculation of the standard deviation. The approximate relationship between the two measures is as follows: Standard Deviation = 1.25 x MAD. For example, to find the standard deviation of forecast errors, over 12 months would ordinarily require a person to add the square of the difference between the twelve forecasts and twelve actual demand readings, divide the total by 11 (ie 12 - 1), and take the square root of the resulting number. Using MAD, all that is necessary to find the MAD is to add the twelve absolute errors between the forecasts and actual demand readings ("absolute" means that errors of -12 and -7 are counted as +12 and +7), and divide the total by 12. Multiplication by 1.25 now gives an approximation to the standard deviation. While MAD no longer has value from the general computing viewpoint, the simplicity of explanation and the arithmetical simplicity of calculations involving it continue to remain very attractive - for example, in getting over to members of staff how to work out system control limits which have been set at the mean plus and minus 3 standard deviations.
MADE: Manufacturing Automation and Design Exploration (proprietary application software).
Madogiwazoku: allegedly, Japanese for employees who have no job but have been retained nevertheless (ie in British parlance, on gardening leave).
Main Purpose Rule: This rule applies in deciding whether an exclusion clause within a contract is or is not valid. Generally, a supplier's exclusion clause must be stated at the outset when the contract is formed. An exception to this exists if the buyer places repeated, regular orders, and becomes - or should become - well aware of the supplier's exclusion. A second exception exists if both parties are "in the trade" and the exclusion is the custom and practice of business. In deciding whether an exclusion clause is valid, the principal which is applied by the courts is the "main purpose rule". That is, in a written contract, the existence of an express exclusion that excludes one or other of the contractual conditions (but not warranties) appears illogical - if the obligation/condition truly exists, the exclusion must therefore be invalid, and if the exclusion is valid, the obligation/condition does not exist! Consequently, to determine whether an exclusion clause relating to a condition is valid, the context and purpose of the contract as a whole must be taken into account by the court.
Maintenance (Autonomous): see Autonomous Maintenance:
Maintenance (Breakdown): see Breakdown Maintenance.
Maintenance (Corrective): see Corrective Maintenance.
Maintenance (Predictive): see Predictive Maintenance.
Maintenance (Preventive): see Preventive Maintenance.
Maintenance Prevention: that aspect of TPM related to how easily the design of equipment lends itself to maintenance - in a word, the machine's maintainability. A mistake in ensuring maintainability is permanent.
Make and Pack: When production is followed immediately by a packing or bottling operation, without any intervening storage of the material just made, the joint planning of the production and packing presents considerable scheduling difficulties (see Co-Products). In continuous flow APS systems, much expertise has been put into dealing effectively with the problems that arise.
Make to Order: Many products required by customers are not held by the manufacturer in stock, but are made ab initio on receipt of the customer's order. The reasons may be the products' expense or degree of specialisation or their required customisation. One problem for the customer in ordering a product on this basis may be the possibility of its eventual late delivery. A problem for the manufacturer may be the financing of the manufacturing operation.
Makespan: somewhat out-of-date shop floor jargon for the time to process a set of jobs.
Manifest: (noun) a list of a ship's cargo signed by the ship's master for use by customs officers (OED).
Manufacture of Pins: In his momentous book "An Enquiry into the Nature and Causes of the Wealth of Nations" (commonly referred to merely as The Wealth of Nations, published in five volumes in 1776), Adam Smith famously points out in Chapter 1 that "one man alone could hardly make a single pin in a day, and certainly could not make twenty". However, by dividing the manufacturing process into some eighteen operations (drawing the wire, cutting it, pointing it ... ), ten men can make 48,000 pins - ie 4,800 pins per person per day. What this illustrates is the advantage, accepted now by all, of the division of labour. The famous Wealth of Nations is held by many to be one of "the books that changed the world". It is readily available from Amazon, although an edited version might be easier going for the modern reader (such as that by Kathryn Sutherland, price £7.19). The famous pin example is referred to on the back of the new UK £20 note, which confusingly states that the division of labour results in an increase in the quantity of work, work being an old-fashioned term for production or output.
Manufacturing Day Calendar: See Shop Calendar.
Manufacturing Logic, The: In the heyday of MRP in the 1980s, this term was used to subsume the following: the netting logic - the activity of subtracting stock on hand from gross requirements to determine net requirements; the exception logic - the determination of any rescheduling necessary to the current due dates of open and firm planned orders to new dates when arithmetic shows they are now needed; and the reporting logic - the display of rescheduling messages to the planner in relation to the exception logic.
Manufacturing Resource Planning: - see MRPII
Manufacturing & Technology News: A useful source of news items relating to manuacturing, geared mainly to US industry. To sign up to their e-mails, go to http//www.manufacturingnews/mailing list.html
Marginal Costing: Synonymous with Costing (Variable).
MARIMA (Multivatiate Autoregressive Integrated Moving Average): A causal forecasting technique better known as Bayesian Forecasting (qv).
Markgrafler: a type of schwundgeld originating in July 2004 in Heitersheim, southwest Germany.
Market Demand: See Demand Patent, and Demand Latent.
Market Pricing: A qualitative job evaluation technique by which company jobs are directly graded by taking note of the rates of pay of seemingly comparable jobs offered by external companies (ie rates within the external market). Care must clearly be taken in market pricing to ensure that outside jobs really are comparable in content, rather than carrying merely the same job title - a small number of management consultancies and institutions publishing yearly salary surveys also include detailed descriptions of the jobs themselves. Note that whatever semi-scientific quantitative job evaluation technique is used, such as point-factor, results from it must bear some reasonable accord with rates in the external market. See also Pay Posture.
Market Research: Market Research is the gathering and analysis of facts relating to the sale of goods. The activity first includes the investigation of markets themselves, such as the determination of their sizes and composition and the preferences of consumers within them. (A "market" might be defined as, say, "young couples with children", or "pensioners living in retirement homes".) Market research also includes, second, an analysis of the activities of marketing itself, such as an analysis of TV viewing habits, vis a vis TV advertising, and the readership of magazines. Market research is carried out by a wide range of organisations, from large multinational companies to one-man bands, including market research sections of large companies. Types of market research include retail audits (for example, as carried out by AC Neilson Inc, which conducts shop audits); syndicated research (surveys of aspects of consumer behaviour); qualitative research (in depth interviews); advertising research; and media research (see JICARS).
Market Share: If the total market demand for a product is 100%, the company's market share is as follows: (actual sales of the product) / (total market demand in units) x 100%. Market share is a vital indicator of a product's prospects - if market share is diminishing, it means that competitors' products are being preferred and chosen either by existing customers or by new ones coming onto the market for the first time.
Marketing Concept: "Marketing is the management process responsible for identifying, anticipating and satisfying customer requirements profitably" ... definition published by the Chartered Institute of Marketing.
Marketing Mix: (PPPP + S) In marketing, it is said that a customer looks for many different aspects of satisfaction in a product. These are (i) P (the inherent product itself ... is it useful and wanted), (ii) + P (price), (iii) + P (place ... how far does he have to go to lay hands on it), (iv) + P (promotion ... the product's aura), (v) + S (service ... does he need and receive help after the sale).
Markov Process (Markov Chain): A mathematical treatment of a situation in which there is a possibility in a given period that a transition may occur from one state to another. In manufacturing, Markov chain theory assists in (1) manpower planning - the likelihood of staff promotions, or likelihood of staff resignations; and (2) in marketing - the likelihood of a consumer switching brands.
Mass Customisation: A term given to two-level master scheduling, or assembly-to-order production. With mass customisation applied to products with many option variants on an otherwise basic structure, the option variants are master scheduled and the final unique configuration of the product is assembled to the customer's requirements from the chosen variants in a so-called final assembly schedule (see also FAS).
Mass Production: Production in high volumes - a somewhat outmoded term.
Master Black Belt: An expert in charge of a number of black belts, in six sigma quality. At the technical level, the master black belt will be very knowledgeable about use of the more "difficult" procedures in the Six Sigma Analyse phase - DOE, ANOVA etc.. At the practical level, the MBB will give advice on team working and company politics.
Master Plan: See Master Production Schedule.
Master Production Schedule: A time phased schedule of plans to acquire (*) material that will thus be available to satisfy anticipated or actual customer demand. (* Acquisition of material will normally be by manufacture, of course, but could be simply the buying in of finished goods for direct resale.) Although there are a few exceptions, only end products are master scheduled. The schedules and plans for lower level components and for raw materials are obtained by exploding the master schedule itself down through the bill of materials. In make-to-stock environments, fulfilment of the master schedule leads to the creation of stock ready to satisfy future orders. In make-to-order, the master schedule is really a schedule of final manufacturing work, since when the stock is produced, it is immediately and directly transferred to the customer for whom it has been made. Note that a number of practitioners define the master schedule as the schedule of manufacture that must be manually created and managed - for example, a master schedule for a metal ore mining operation may be the actual mining programme, rather than the plans to despatch the final washed ore. Two important subjects closely associated with master scheduling are Sales & Operations Planning and rough cut capacity planning. Note also that the full text, illustrated course.
Master Schedule: See Master Production Schedule.
Materials Costs: In relation to product costing, materials costs are expenditures incurred relating to "things" such as raw materials, rather than costs relating to labour or expenses. Materials costs may be direct or indirect. Contrast "Labour Costs" and "Expenses".
Materials Management: A composite term for all those procedures and actions which govern the manufacture of product and the disposition of inventory. Examples of procedures may include: master scheduling; materials planning; distribution; and others such as sales forecasting. In addition, materials management may include the setting of manufacturing lot quantities and the management of forecasts and safety stocks. See also Inventory Management.
Materials Movement (Discontinuous): Movement effected by lifting equipment (winches, pulleys); mobile equipment (FLTs); stacker cranes; or order pickers.
Materials Movement (Continuous): Movement effected by towing mechanisms; powered conveyors; roller conveyors; and continuous propelling mechanisms (eg elevators).
Materials Requirements Planning: see MRP
Mathematical Programming: A number of combinatorial optimisation techniques used extensively in very many applications throughout manufacturing industry to find "best", or optimal, solutions in the face of limited resources. In mathematical terms, "best", or optimal, means the maximisation or minimisation of a so-called objective function. The best known family member is linear programming, allowing solutions involving decimal fractions. Integer programming is more complex than linear, but can confine solutions to whole numbers. Dynamic programming allows the user to specify changes to the ranges and constraints of the model as calculation proceeds. Mixed Integer programming is a combination of linear and integer.
MBB: In Six Sigma, a Master Black Belt (qv).
MBWA: Management By Wandering (or Walking) Around - the management by the manufacturing manager of the actual production workplace, closely observing matters and taking note of control charts and other evidence as to the state of machines, set-up times, quality and so on. MBWA is associated with Just-in-Time environments, although it is clearly applicable universally. MBWA is an activity associated with continuous improvement.
MC: Mass Customisation, qv.
MCS: Manufacturing Control System, or Multiple Constraint Synchronisation.
Mean Time to Failure (MTTF): A critical measure of component reliability, estimated when a product is under design by consideration of its observed failure rate and the application of either the exponential distribution or the Weibull distribution to the probability of its survival. The MTTF is customarily denoted by the Greek letter theta, and is equal to 1/(failure rate).
Mean Square: = Mean Square Deviation from the Mean, synonymous with variance, qv.
Mechanistic: When applied to human resources, an organisational structure defined by authority and command - see "hierarchy".
Media Research: the conduct of market research in order to find which types of consumers read which magazines and newspapers, and watch which TV programmes. In the UK, consumers are classed by the JICARS classification (qv) into seven social groups as follows: (1) higher management and professional (eg directors, accountants); (2) lower managerial and professional (eg supervisors, bank managers); (3) intermediate occupations (eg machine operators, policemen); (4) small employers and sole traders (eg self-employed builders, farmers); (5) lower supervisory and technical (eg plumbers, bakery workers); (6) semi-routine occupations (eg security guards, postmen); and (7) routine occupations (eg bricklayers, cleaners). The classification scheme was introduced in 2001, replacing a long-established six-class system (see * below). The changes were felt necessary because of the decline in the number of blue collar workers and the increase in numbers of white collar workers and working women. The previous 6-class scheme was (A) higher managerial (3%), (B) intermediate managerial, administrative and professional (12%), (C1) supervisory, clerical , junior administrative and junior professional (29%), (C2) skilled manual (29%), (D) semi-skilled manual and unskilled (19%), and (E) state pensioners, widows, casual and low earners (8%).
Memorandum of Association: along with the articles of association (qv), one of the two key founding documents of a company, the memorandum showing the origin of the company's capital and setting out its name and trading objectives.
MEMS: Micro-electronic mechanical system. A device incorporated in a sensor or actuator which converts a physical condition into an electronic system or into a data element. An example is an actuator which converts an electrical signal into a garage door opener. An RFID tag is not a MEMS device - the RFID signal needs a further device or system before physical action is taken.
Merchandising: The management of retail sales operations, encompassing such subjects as the layout of the stores or shop, ensuring the best mix of goods is available to buy, advertising displays, stock availability and facilities for actual purchase.
MES: Manufacturing Execution System, a term that never quite made it, and intended to cover the area between general materials planning and the actual detailed scheduling on the shop floor. "MES" has probably been subsumed by the more popular acronym APS (qv).
Meta Heuristic: An overall search strategy which guides the operation of a subordinate heuristic. The guiding principle of a meta-heuristic is usually derived from artificial intelligence studies (AI), mathematics, biological science or physics. For example, techniques borrowed from physics include observations and studies of "annealing" - the controlled heating or cooling of a liquid.
Metric System: see conversion factors.
Metrology: The science of weights and measures, but a term more often used in relation to the practice and procedures in using measuring devices within industry and the problems associated them. See also Gauge R&R.
Mezzanine: A low storey between two others, usually in general buildings between the ground floor and the storey above. A mezzanine floor has also been defined as "a raised platform independent of the host building structure, supported by steel columns". (Two further dictionary meanings are: (1) a small window that is less in height than breadth, and (2) a floor beneath a theatre stage.) In logistics and in the context of warehouses, a mezzanine floor creates additional floor space and is usually seen as a rapid, cost effective alternative to re-locating, with minimum disruption to on-going operations. Mezzanine floors must comply with BS5950 (parts 1 & 5) and BS6399. Floors are usually made of steelwork with a choice of decking, and can typically be installed in a few weeks. For further information on the subject, (1) see sub-section 1.2.1 of the free on-line stores course on stores at this site, or (2) at be aware that Link 51 Ltd has produced a 40 page guide to the subject (Guide to Building Regulations for Raised Storage Areas and Mezzanine Floors). Contact Link 51 - phone 0800-169-1515, or email at sales@link51.co.uk or through www.link51.co.uk.
MHE: Mechanical handling equipment.
MHz: Megahertz, or millions of cycles per second.
MIL STD 105E: A military sampling table issued in 1989, and one of a family of such tables going back to 1942.
Military Sampling Tables: Sampling tables originally devised in World War II in relation to the acceptance from suppliers of ordnance by the US Army.
Millihelen: that degree of feminine beauty that will launch exactly one ship.
Minitab: A long-establised and well regarded commercial statistical software package that has been found especially useful in the Data Analysis phase of the Six Sigma DMAIC procedure. Minitab is easy to use, powerful and reasonably priced - in the UK, phone 0124-7643-7500 (Coventry). Also visit http://www.minitab.com.
Min/Max System: See Order Point System.
MIS: Management Information System.
Misfeasance: legal parlance often reserved for a breach of duty to a company committed by a director.
Misrepresentation (legal): - a statement made by one party about some matter that induces another party to enter into a contract relating to the matter, even though the facts of the statement are not themselves directly incorporated in the contract. (For example, the supplier of a second-hand machine tool may make a representation that the machine he is selling has done only 10,000 hours of work, although the number of hours done by the machines is not in the contract.) Misrepresentation can give rise to legal liability and, if it is fraudulent rather than innocent, even criminal prosecution. It is divided into three classes: (i) misrepresentation of fact - the supplier has made an untrue statement about a factual matter; (ii) material misrepresentation - the fact which has been misrepresented is inherently important, and is not a triviality; and (iii) the misrepresentation induced the contract. In the last case, the aggrieved party will go to the courts to seek "equity" - ie seek a return to his financial situation before the contract was entered into.
Mistake Proofing: see Poka Yoke.
Mistake (legal): A contract can be brought to an end due to a central mistake that is either (1) common to both parties; or (2) mutual, or (3) unilateral. Mistake here has a legal meaning: it never has the everyday meaning of misjudgment or lack of wisdom. First, let it be said that the old expression caveat emptor is a powerful argument in denying the claim that a mistake has occurred in a contract such that the contract is void. Caveat emptor is Latin for beware the buyer, and means that the buyer should be most careful in what he purchases. If he buys something unwisely, he has only himself to blame. One might also add the expression caveat venditor, beware the seller. Nevertheless, suppose that the buyer knows that the supplier is making a mistake in agreeing to a contract. In this case, the buyer can enforce the contract only provided the mistake concerns matters of fact. Things are different if the mistake concerns the terms of the contract themselves. For example, suppose the buyer knows the supplier is mistaken as to the terms of the contract - ie the buyer knows that the supplier thinks the contract contains term X, whereas in fact the contract actually contains term Y instead. In such a case, the buyer cannot enforce the contract in the sense of term Y, even though the contract which both parties signed states Y, not X. An example of this was a contract stating a building was to be completed in 30 months, which the contractor thought was 18 months. (The contractor had not read the contract properly.) The court ordered the duration in the contract to be changed from 30 months to 18 months, because it (the court) was satisfied in the circumstances that the written words (30) did not represent the true contract between the parties. This was an 18 month contract because the other party knew at the time that the contractors believed it was an 18 month contract. As a final statement, the buyer should know that whenever it is to be inferred from the terms of a contract that the agreement has been reached on the basis of a particular contractual assumption, and that assumption turns out not to be the case, the contract is void from the start. See the free on-line purchasing 'course' at this site.
Mixed Integer Programming: See Mathematical Programming.
MMS: Materials Management System.
Mode: The most frequently occurring value in a distribution. For example, if we take the ages in years of all pupils at The Manchester Grammar School, the most frequently occurring age may be 14 years - ie in this case,14 years is the mode. If two ages had the same frequency, say 14 years and 16 years, the population of pupils is said to be bi-modal with regard to age. In manufactured quality, the distribution of some quality characteristic may be bi-modal if the parts in the population have been screened out or rejected. (For example, 40% of the parts may have been rejected, leaving only those parts with readings in two narrow, distinct ranges of values.)
Mode (of Transport): The general means by which transportation is to proceed - ie whether by road, rail, sea or inland waterway*. (* Inland waterways include canals and rivers, and constitute major freight carrying routes in continental Europe.) Multimodal means transport involving two or more different modes - for example, the transport of goods first by road to a port, then by ship to another port and then by train to a final destination is a multimodal journey involving three modes.
Modular Bill of Materials: The word "modular" means pertaining to a module, a module being an alternative term for an option. It would be confusing, however, to refer to a bill as optional, ie pertaining to an option. - hence the choice of the term modular. The modular bill of materials is a means of making clear which option types are available, and which variants are available relating to each option type.
Money Equation, The: This famous equation is held to be central by the economics guru Milton Friedman and other economists who reject "Keynesianism". The Equation states MV = PT, where M is money quantity, V is velocity of circulation, P is price levels, and T is transactions.
Monopolies and Mergers Commission: A body corporate based in the City of London which will examine any proposed merger between companies which may result in the merged companies having a market share of 40% or more of some product or service. The Commission is empowered to block any such merger it sees as being "against the public interest" - ie which it sees as creating a monopoly situation and therefore being potentially inimical to competition.
Monopoly: The sole supplier of a good or service. Theoretically, the monopolist can dictate the price of what he sells, since there is no competition. In practice, he must be careful - the customer forced to pay an excessive price will seek substitutes or alternative paths of business - see the "Dynamic Market".
Monopsomy: The market condition where there are many sellers of a good, but only one buyer. The situation arose in the "command economies" - ie the old defunct communist economies and others controlled by the state. A market condition with many sellers but few buyers is termed an oligopsomy. In the UK, a manufacturer of grocery products might believe he is in an environment such as this vis-a-vis the big supermarket chains.
Month (Calendar): One of the twelve months of the year. If calendar months are used in time-series forecasting, an adjustment must be made to account for the different number of trading days in each one. For example, the average number of trading days in a month may be 26.1 (ie one twelfth of the total number of trading days in a particular year), so that a demand of 1000 units in February (say, 22 trading days) will be considered for forecasting purposes to be (1000 / 22) x 26.1 units.
Month (Costing): Cost accountants may divide the year into 13 months of 4 weeks each, to avoid the problem described under Month (Calendar). A problem for those using the system, however, is that they must recognise that CP7 (cost period 7) is not July, but only part of the calendar month July.
Moore's Law: Computer processing speed tends to double every 18 months.
Move Ticket: A brief document authorising the movement of material on the shop floor, either to the next operation or into stock. A shop floor can be plagued by unauthorised materials movements, making it difficult to track jobs, and the insistence on move tickets is an attempt to mitigate the problem.
MOS: Metal Oxide Semiconductor.
MPEG1: Moving Pictures Expert Group 1. (A video file compression format used on Video CDs.)
mph: miles per hour.
MPS: See Master Production Schedule.
MRO: See Stock (MRO).
MRP (Materials Requirements Planning and Closed-Loop MRP): In common parlance, MRP may mean Manufacturer's Recommended Price. To the manufacturing professional, however, MRP is a computer-centred system for creating and maintaining a set of manufacturing and purchasing plans so as to support the manufacture of a master schedule (see, importantly, MPS). The initial creation of the materials and purchasing plans is carried out by "exploding" the MPS through successive levels of the bill of materials of the master schedule products. More pertinently, the plans so created by this explosion can be kept up-to-date and synchronised with the on-going MPS by feeding information back into the MRP system as it relates to manufacture that has now been completed and the latest stock quantities to hand. After the feedback, the planning calculations can be rerun and differences noted from the previously calculated requirements. The performance of this feedback, recalculation and reporting of differences is referred to as "closed-loop MRP", and the feedback itself is referred to as closing the loop. (Closed-Loop MRP has its origins in a development by IBM in 1965, although the methodology is often attributed to work in 1971 by Joseph Orlicky, George Plossl and Oliver Wight - that is, before the age of telecommunications systems, graphics and interactive computing.) Most companies investing in Closed-Loop MRP systems have experienced truly dismal returns for the time and money spent, but a large army of software vendors, consultants and trainers have managed to convince them that the reasons for their failure are mainly their own. The methodology can be made to work where manufacturing proceeds in disjunctive steps, each step taking a relatively lengthy time (ie days, not hours). It is least likely to be successful where manufacturing steps are relatively short in duration and, perhaps, where daily decisions on procedures must be made by planning staff. Closed-Loop MRP seems now to have been displaced by APS, a more practical and successful approach. In studying MRP, the student would do well to separate the mechanism of materials planning (eg the bill of materials explosion) from the activities involved in closing of the loop. The result of splitting the overall subject in this way is for the reader to gain considerably greater clarity of understanding.
MRPII (Manufacturing Resource Planning): A term coined in 1974 by the late Oliver Wight, whose vision it was, to mean an integrated system of such system components as: closed-loop MRP; MPS; Shop Floor Control; Sales Order Processing; Accounting; and other elements of manufacturing business - see also ERP.
MTBA: Mean Time Between Assists.
MTO: Make to Order, qv.
MTS: Make to Stock.
MTTF: See "Mean Time To Failure".
MTTR: Mean Time To Restore, or Mean Time To Respond.
Multi Model Forecasting Systems: Many proprietary forecasting packages, such as Demand Solutions, Focus Forecasting and Forecast Pro, consist of some 20 or 25 different forecasting techniques, or techniques with different parameters. All of the techniques and models are run each month in parallel. The forecast issued to the user is the one emanating from that technique or model which proved most accurate in the previous month. Consequently, the forecasts issued from one month to the next could each have a different basis depending on the winning techniques / models. Doubts arise in multi model forecasting regarding (1) the effect of the constant switching of the forecast basis on the long leadtime forecasts used, say, in master planning; (2) the failure of the forecast user to get to know a specific model and refine its operation; and (3) the laconic observation that the incorporation of 20 techniques is of little value if they are all inferior. Nevertheless, multimodel systems are likely to yield reasonably satisfactory results, and appear not to be expensive (*) compared with the cost of more sophisticated systems such as those using Bayesian Forecasting. It is surprising that academic personnel have not conducted simulations of contending techniques in the way that they conducted simulations in the past relating to Despatching Rules. (* Dragging the prices of their products out of forecasting software vendors is like pulling teeth, leading one to suppose that a price is often what a salesman thinks he can get at the time.)
Multi-Level Master Scheduling: The independent master scheduling of items at two or more levels in a bill of materials. An example is the master scheduling of bottled whisky and the independent master scheduling of the distillation of whisky - although they share the same bill of materials, the activities are separated in time by many years. Note that multi-level master scheduling is akin to the scheduling of co-products and is not the same as two-level master scheduling.
Multi-Level Pegging: see full pegging in the Glossary entry for pegging.
Multi Site Netting: When one factory is responsible for the production of material M, and Material M is actually used at a second company factory site, it is necessary to formulate plans for the production of M by considering the net requirements at the second consuming site and the transit times between the two.
Multiple Netting: See Multi-Site Netting.
Multiple Sampling: an ingenious extension of double sampling, involving the taking of many samples of size n1, n2, n3 ... each having an acceptance criterion c1, c2, c3 .... Multiple sampling is not especially more effective than double sampling, and is far harder to administer.
Murphy's Law: A rule ascribed to by the cynical, the weary and those who have been too long in manufacturing industry, that what can go wrong, will go wrong either (a) at the worst possible moment for doing so, or (b) as soon as one takes his eye off it. See also O'Leary's Corollary.
