ការអនុវត្ត និងទ្រឹស្តី នៃ ការដឹកជញ្ជូន ( Logistics. Theory and Practice )
សូមស្វែងយល់ អំពីមេរៀននៃការដឹកជញញជូនដូចខាងក្រោម! (Logistic lesson)
Logistics is the art of managing the supply chain and science of managing and controlling the flow of goods, and controlling the flow of goods, information and other resources like energy and people between the point of origin and the point of consumption in order to meet customers' requirements. It involves the integration ...
Logistics. Theory and Practice.
Origins and definition
- The word of logistics originates from the ancient Greek logos (λόγος), which means “ratio,
word, calculation, reason, speech, oration”.
- The branch of science having to do with procuring, maintaining and transporting material,
personnel and facilities.
Logistician
- Sea
- Air
- Land
- Rail
Military logistics
In military logistics, logistics officers manage how and when to move resources to the places they are needed. In military science, maintaining one's supply lines while disrupting
those of the enemy is a crucial—some would say the most crucial—element of military stratagy, since an armed force without resources and transportation is defenseless
Medical logistics
Medical logistics is the logistics of pharmaceuticals, medical and surgical supplies,
medical devices and equipment, and other products needed to support doctors, nurses, and other health and dental care providers.
Business logistics
Inventory management
Purchasing
Transportation
Warehousing
This can be defined as having the right item in the right quantity at the right time
at the right place for the right price.
Supply Chain Management Problems
Supply chain management (SCM) is the process of planning, implementing, and controlling
the operations of the supply chain as efficiently as possible. Supply Chain Management spans all movement and storage of raw materials, work-inprocess inventory, and finished goods from point-of-origin to point-of-consumption.
- Distribution Network Configuration: Number and location of suppliers, production facilities,
distribution centers, warehouses and customers.
- Distribution Strategy: Centralized versus decentralized, direct shipment, Cross docking, pull
or push strategies. Information: Integration of systems and processes through the supply chain to share valuable information, including demand signals, forecasts,
inventory and transportation
- Inventory Management: Quantity and location of inventory including raw materials, work-in-process and finished goods.
- Cash-Flow: Arranging the payment terms and the methodologies for exchanging funds across entities within the supply chain.
Activities/functions
Strategic
Tactical
Operational
Strategic
Strategic network optimization, including the number, location, and size of warehouses,
distribution centers and facilities.
Strategic partnership with suppliers, distributors, and customers
Product design coordination so that new and existing products can be optimally integrated into the supply chain, load management
Information Technology infrastructure to support supply chain operations.
Where-to-make and what-to-make-or-buy decisions
Aligning overall organizational strategy with supply strategy.
Tactical
Sourcing contracts and other purchasingdecisions.
Production decisions including contracting,locations, scheduling, and planning process
definition.
Inventory decisions including quantity, location, and quality of inventory.
Transportation strategy including frequency, routes, and contracting.
Benchmarking of all operations
Milestone payments
Operational
Daily production and distribution planning
Production scheduling for each manufacturing facility in the supply chain (minute by minute).
Demand planning and forecasting , coordinating the demand forecast of all customers and sharing the forecast with all suppliers.
Sourcing planning , including current inventory and forecast demand, in collaboration with all suppliers.
Inbound operations-transportation from suppliers and receiving inventory.
Production operations
Outbound operations--fulfillment activities and transportation to customers.
Order promising, accounting for all constraints in the supply chain, including all suppliers, manufacturing facilities, distribution centers, and other customers.
Production logistics
The term is used for describing logistic processes within an industry. The purpose of production logistics is to ensure that each machine and workstation is being fed with the right product in the right quantity and quality at the right point in time.
Theoretical view
A sigmoid function is a mathematical function that produces a sigmoid curve — a curve having an "S" shape. Often, sigmoid function refers to the special case of the logistic function
Cumulative distribution function
The logistic distribution receives its name from its cumulative distribution function (cdf), which is an instance of the family of logistic functions:
Logistic regression
logistic regression is a model used for prediction of the probability of occurrence of an event. It makes use of several predictor variables that may be either numerical or categories. Logistic regression is used extensively in the medical and social sciences as well as marketing applications such as prediction of a customer's propensity to purchase a product or cease a subscription.
For example, the probability that a person has a heart attack within a specified time period might be predicted from knowledge of the person's age, sex and body mass index.
Lay explanation
An explanation of logistic regression begins with an explanation of the logistic function:
The logistic function, with z on the horizontal axis and f(z) on the vertical axis.
The "input" is z and the "output" is f(z).
The logistic function is useful because it can take as an input, any value from negative infinity to positive infinity, whereas the output is confined to values between 0 and 1. The variable z represents the exposure to some set of risk factors, while f(z) represents the probability of a particular outcome, given that set of risk factors. The variable z is a measure of the total contribution of all the risk factors used in the model and is known as the logit.
The variable z is usually defined as
where β0 is called the "intercept" and β1, β2, β3, and so on, are called the “regression coefficients" of x1, x2, x3 respectively.
The intercept is the value of z when the value of all the other risk factors is zero (i.e., the value of z in someone with no risk factors). Each of the regression coefficients describes the size of the contribution of that risk factor. A positive regression coefficient means that that risk factor increases the probability of the outcome, while a negative regression coefficient means that that risk factor decreases the probability of that outcome; a large regression coefficient means that that risk factor strongly influences the probability of that outcome;
while a near-zero regression coefficient means that that risk factor has little influence on the probability of that outcome.
The application of a logistic regression may be illustrated using a fictitious example of death from heart disease. This simplified model uses only three risk factors (age, sex and cholesterol) to predict the 10-year risk of death from heart disease. This is the model that we fit:
β0 = − 5.0 (the intercept)
β1 = + 2.0
β2 = − 1.0
β3 = + 1.2
x1 = age in decades, less 5.0
x2 = sex, where 0 is male and 1 is female
x3 = cholesterol level, in mmol/dl less 5.0
( Countinues.....!!!)
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