Days of Inventory

Days of inventory is a measure used by production management teams. It is calculated by dividing inventory on hand by average daily inventory usage. The result is an initial estimate of the number of days production could continue using just materials on hand. Further insights can be obtained by looking at specific types of inventory (raw-materials inventory, work-in-process inventory, and finished-goods inventory).

Days sales outstanding


Days sales outstanding (DSO) measures the speed at which a company collects accounts receivable from those who owe it money. Some companies may have 40 DSO, while others have created ways to collect money almost immediately on shipment of the product and others may not be paid for months by customers.

Debt-Adjusted Cash Flow (DACF)

DACF is used to reduce distortions in cash flow figures. Distortions arise from different financing methods, and the different accounting methods related to these financing methods. DACF is mainly used when there is substantial debt, large cash flows, and significant impact of tax treatment. This is not unusual in oil and gas companies. DACF smooths out the differences, so that DACF figures can be compared across companies to help assess relative performance and valuations. If companies handle exploration costs in very different ways, then an adjustment for exploration is included in the DACF calculation which is: cash flow from operations + financing costs (after tax), and sometimes + exploration expenses (before tax) +/- working capital adjustment.


In the oil and gas sector, definition is the name of an upstream process which determines how a resource (a reserve of oil or gas) can best be recovered and exploited.

Demand Flow Scheduling Systems

A demand flow scheduling system uses customer orders as the basis for calculating production schedules. This is central to demand-based manufacturing strategies, which generally require good cooperation along the supply chain.

Department of Defence, US, (DoD)

The published mission of the DoD is to provide the military forces needed to deter war and to protect the security of the USA. The military consists of seven armed forces (army, marines, navy, air force, space force, coast guard and national guard); eleven combatant commands with regional or functional roles; plus supporting capabilities.


Desalination a set of processes to remove salt and minerals from seawater. The result is water for human consumption or agricultural use.  Water from desalination is usually more expensive than other sources, so is generally found in regions with limited water supply, and also on ships and submarines.

Design for Assembly

The practice in which ease and cost of assembly is emphasized during the product-design stage.

Design for Logistics

The practice in which physical handling and distribution of a manufactured product are emphasized during the product-design stage.

Design for Manufacturability

The practice in which ease and cost of manufacturing, including quality-assurance issues, are emphasized during the product-design stage.

Design for Procurement

A practice in which product designers work effectively with suppliers and sourcing personnel to identify and incorporate components, technologies or designs that can be used in multiple products. This facilitates the use of standardized components to achieve economies of scale and assure continuity of supply.

Design for Quality

The practice in which quality assurance and customer perception of product quality are emphasized as an integral part of the design process.

Design for Recycling/Disposal

The practice in which ultimate disposal and recycling of the manufactured product are considered during the product-design stage.

Digital marketing

Digital Marketing is the discipline of promoting products and services to consumers through various electronic media, including the internet, mobile, and email.

Digital Mock Up (or Virtual Product Mock Up)

Often called ‘DMU’, these systems generate images of an assembly of parts from various sources and check for fitness for purpose, interference etc. This concept was required by early design systems which handled only individual components. Therefore, to see a complete product, this additional step was required. Now that most design systems handle assemblies and whole products, the emphasis has moved to realistic graphics combined with effective simulation.

Discrete Manufacturing

Discrete manufacturing handles components, assemblies and products which are distinct items. Examples include automobiles, machines, and consumer electronics. Discrete manufacturing contrasts with process manufacturing, which uses liquids, gases, and powders to make products which are usually measured by weight and volume, for example, food, gasoline, chemicals and paint.

Disruptive technology

A disruptive technology or disruptive innovation is an innovation that satisfies a market requirement in unexpected ways, or creates a new market requirement. Examples include cellphones; the compact disc replacing magnetic tape for recording; and digital cameras replacing film-based cameras.

Distributed Control System


A DCS is a real-time, fault-tolerant control system for continuous and complex batch-process applications. Over time, DCS technology has evolved from proprietary, special purpose hardware and software to more use of standards, although proprietary communication protocols remain common.


A distributor buys and stocks products, and then sells them to other businesses. For manufacturers, this simplifies distribution. For buyers, the distributor may offer more suitable buying conditions such as packaging and delivery. In the retail sector, a distributor may be called a wholesaler.

Document Management System

Allows users to store, search, and manipulate documents electronically and to track and manage document versions, status and distribution.

Downstream Operations

In the oil and gas sector, downstream starts at the point extracted oil and gas is first delivered to storage or refinery facilities. Downstream operations take these materials, convert them into fuels, chemicals and other products, and deliver these products to motorists, airlines and many other industrial users.


Periods when a computer, piece of equipment, or manufacturing system is not available to perform work.


In transportation and logistics, drayage refers to movement of containers between transport modes, e.g. from ship to rail.

Dual Use Products

Dual Use Products (sometimes Dual Purpose Products) is the phrase used in UK and US regulations to cover export licensing of products with both civilian and military applications. Examples include radar equipment, heavy road vehicles and civil airliners suitable for reuse as tankers.

Dynamic scheduling

A dynamic scheduling capability allows refinement of production schedules as conditions change. Dynamic scheduling software gathers order, capacity, inventory and supply data, and runs multiple simulations to find the optimal scheduling solution.