The mean absolute deviation or MAD as it is often abbreviated, of a dataset is the average or "mean" distance between each data point from the data set and the mean/average.  This will give you an idea of the amount of variability in a dataset.  MAD can be calculated from both observations and the arithmetic average (mean) of those observations.  Another option when calculating MAD is to calculate based on actual data minus forecasted data.  If forecasting or being used for future analysis you can apply different weights to your forecast or use exponential smoothing in an attempt to make your forecast more accurate.  In most cases however mean absolute deviation uses actual data.

  Internal Move kanbans are essentially permission to retrieve or move materials or information.  The move kanban authorizes one point of a process to get what they need and move it.  Many cards will show the consuming location and the supplying location so that the person moving the tagged item knows where to move too.  Let’s look at a very basic example of how the move kanban works.

  A make to order production environment is one in which manufacturing or in the case of a service, service, starts only after receiving a customer's order. 

Material Requirements Planning is best defined by The Apics Dictionary which is noted below.  A set of techniques that uses the bill of material data, inventory data and the master production schedule to calculate requirements for materials.

  Manufacturing lead time is different than lead time.  Manufacturing or production lead time is the total amount of time it takes to "manufacture" or "produce" an item.

​  MRO inventory stands for maintenance, repair, and operations inventory.  In general it is used to maintain or repair items that are used in operations.  This can include all the supplies an organization uses for its production processes that do not become a part of an end product or finished goods.

  The waste of motion or movement is any motion or movement by people and or machines that does not add or create value.  Motion waste is oftentimes confused with transportation waste, they are not the same.  The easiest way to identify the difference between the waste of motion and the waste of transportation is that transportation waste moves “stuff” or information and generally occurs between process steps and workstations rather than within them.  Motion waste on the other hand, directly relates to people and machines.

To mechanize is to equip with machinery.  Mechanization is a last resort and should only be performed when every possible effort has been made to improve your process times.  You may be wondering, why? 

  Muri is the overburdening of operators or equipment.  Muri often asks or sometimes requires either people or machines to work much harder and much longer than a regular or "appropriate" schedule would. 

  Along with Mura and Muri, Muda is one of the three origins of waste.  The phrase muda means uselessness or wastefulness.  There are two types of Muda that are non-value added activities.  

  Along with muda and muri, mura is one of three origins of waste.  Mura is the unevenness or variability in a workplace.  The term mura originated within the Toyota Production System.  Mura often causes disruptions in flow, throughput and places unnecessary strain on employees.  

Manufacturing is the process or series of interrelated steps by which a company produces by hand or by machine a product. Once the goods are complete they become a finished good.  The manufacturing process can include:

• Research and Development.
• Selection of materials to be used.
• Planning.
• Production or Transformation of Materials.
• Management of all aspects.
• Quality assurance.
• Marketing.

  Multiple Regression is a form of regression analysis that explains the relationship of "multiple" predictor or independent variables with one dependent variable. 

  A moving average is a statistical technique that can be used to get a better understanding of the trends within a (X) number of periods or a data set.  It does this by gathering the average of a defined subset within a series of numbers. 

  The mission of an organization is often depicted as a statement.  It is a written statement which defines an organization's core purpose.  According to the business dictionary a properly crafted mission statement:

1. Serves as a filter to separate what is important from what is not. 
2. Clearly state which markets will be served and how.
3. Communicates a sense of direction to the entire organization.

  The mission can be described as the causal factor, which ultimately creates or moves the company in the direction of the vision (effect).  Another way to discern or understand the difference between an organizations vision and their mission is to look for the difference between future and present.  A vision is future based.  It is "where" you are headed.  The mission on the other hand explains why the organization exists.  

Reference: Business Dictionary - Mission Statement

  A make to stock production strategy is used mostly in forecasting environments.  The Apics dictionary 14'th edition defines Make to Stock as a production environment where products can be and usually are finished before receipt of a customer order.  Customer orders are typically filled from existing stocks and production orders are used to replenish stocks.

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  A water spider/runner/mizusmashi is someone who transports materials quickly and efficiently from work area to work area.  Typically the water spider will collect, deliver and log the flow of materials as they move from area to area.  This person will also attempt to move as much non-value added work away from the primary member.

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  A material information flow diagram is a value stream map.  Toyota refers to the map as material and information flow because the map visually shows the flow of materials and information.

See also: Value Stream Map.

  Mixed-Model Production is the practice of making, assembling or producing several different parts or products (this can also be applicable to services) in varying lot sizes so that the organization produces close to the same mix of products/services that will be sold on the same day.  The goal of a mixed-model production tactic is to smooth out the demand of upstream workcenters, cells, suppliers and vendors which results in a reduced inventory, faster changeovers and more accurate replenishment of products ultimately working towards building and or producing in accordance with daily demand.

The Master Production Schedule (MPS) is best defined by The Apics Dictionary, which is cited below.
​  A line on the master schedule grid that reflects the anticipated build schedule for those items assigned to the master scheduler.  The master scheduler maintains this schedule and material requirements planning.  It represents what the company plans to produce expressed in specific configurations, quantities and dates.  It is not a sales item forecast that represents a statement of demand.  It must take into account the forecast, the production plan and other important considerations such as backlog, availability of material, capacity and any other management policies and goals.

​Ref: Apics 

  Business Metrics are a system for collecting, measuring and benchmarking a measure to an established standard or a specific objective for a department, operation, product, service, business, organization etc. A good performance metric will establish criteria, a standard or desired level of performance and a measurement.  One of the greatest books on Metrics is; Metrics, how to improve key business results.