Glossary - D
Damage 
      Damage is the severity of injury or the physical, functional, or monetary loss         that could result if control of a hazard is lost. Source:         S1 
Danger 
      Expresses a relative exposure to a hazard. A hazard may be present, but there         may be little danger because of the precautions taken. Source:         S1
Database 
      A collection of data arranged in an ordered manner; it can be used for many         applications and by many programs. It is independent of the programs that         use it. Meaningful information is extracted from the data to facilitate         informed decision-making. Source: G1 
Data Capture 
      The encoding of data including map digitizing, direct recording by electronic         surveying instruments, and the encoding of text and attributes by whatever         means. Source: G1 
Data Management 
      The management of data that is held within the computer system to ensure its         structure complies with the requirements and specifications of the system.         Source: G1 
Decision Tree 
      A method of representing a series of events in terms of a combination of smaller,         simpler, more manageable, independent segments, with the smaller segments         arranged as the branches of a tree and with each event given a probability         with respect to the decision alternatives for each event. Source:         T4 
Decommission 
      Activities required to take an asset out of service. Source:         P1 
Defects Liability Period 
      The specified period of time within which the contractor is required, at the         contractor's cost, to rectify any defects in the completed works due to         faulty materials or workmanship, and notified in writing by the Principal.         The period commences from the date of issue of the "Certificate of Practical         Completion" and lasts for the period stated in the contract. Source:         P1
 Deferred Maintenance 
      Maintenance that is due to be carried out in the current financial year but         which will not be carried out because of shortage of funds or unavailability         of parts. Deferred maintenance should be added to the backlog of maintenance         items awaiting attention. Source: P1 
Demand and Customer Expectations 
      The demand for services and expectations of level of service expected by the         users of the service. Source: G1 
Demand Management 
      The active intervention by a service provider, at any stage of the service         delivery cycle, for the purposes of influencing the demand for the service         within financial, social and political constraints. Source:         P1 
Demand Side Management (DSM) 
The activities involved in managing the demand for our assets both strategically   and operationally (e.g. load shedding). 
Depreciation (Economic) 
      Depreciation in an economic sense, is the same as the asset consumption.         In effect it relates to the decrease in the value of a capital asset due         to use, wear and tear, physical degradation, obsolescence through technological         or market changes, ageing or any other cause that reduces its useful economic         life, or due to obsolescence through technological or market changes.         The notional amount of money involved in the decrease in value is regarded         as a cost. Sources: G1 & A4       
Depreciation (Financial) 
      An accounting practice that aims to distribute the cost or other basic value         of tangible assets, less salvage value if any, over the estimated useful         life of the assets in a systematic manner. Source:         G1 
Deprival Value 
      The cost to an entity if it were deprived of an asset and was required to continue         to provide services and/or goods, or deliver programs without the use         of that asset. Assets are valued at an amount that represents the entire         loss that might be expected to be incurred if the entity were deprived         of the service potential or future economic benefits of these assets at         the reporting date. Deprival value may also represent an opportunity value,         i.e. the cost avoided as a result of having control of an asset. Sources:         G1 & A4
 Design Life 
      The proposed life of the asset determined as part of the design process. It         becomes an input into the design criteria. Source:         G1 
Detection 
      In an FMECA process, detection is an assessment of the likelihood that the         current controls (design and process) will detect the cause of the Failure         Mode or the Failure Mode itself, thus preventing it from reaching the         customer. Source: A4 
Deterioration Rate 
      The rate at which an asset approaches failure. Source:         A4 
Digital Mapping 
      The process of acquisition (capture), transformation, and presentation of spatial         data held in digital form. Source: G1 
Digitizing 
      The process of converting analogue (graphic) maps and other sources to a computer         readable format. Source: G1 
Direct Cost 
      A cost item that can be traced specifically to an output in an economically         feasible way. Source: G1 
Discounted Cash Flow 
      The current value (in today's $ value) of all future cash flows to be generated         by a development project. Source: T4 
Discount Factor
      A percentage rate used to convert monetary values occurring at different times         in the future, to values at a common point in time, generally the current         year. Source: A4 
Discount Rate 
      An interest rate at which costs and benefits in future years are discounted         to represent them in present day values - to convert the value of all         future dollars to the value of dollars at a common point in time, usually         the present. It is wise to check with Finance to obtain the current discount         rate. This also facilitates sensitivity testing. For instance, if the         current discount rate was advised to be 7%, then sensitivity testing at         4% and 10% could be conducted. Source: A4       
Discount Year 
      The base year to which costs and benefits are discounted to arrive at a present         value. It is most usually the current year. Source:         T2 
Discounted Payback Period (DPP) 
      The elapsed time between the point of initial investment and the point         at which the sum of the present values of benefits to date equals the         sum of the present values of costs to date. Source:         T1 
Discounting 
      The process of converting money values that occur over different years to a         common year (discount year), to enable comparison between options. Source:         A4 
Disposal Cost 
      Certain activities are often necessary to dispose of a decommissioned asset.         The costs associated with such asset disposal are recognized as part of         the life cycle costs of the asset. Source: A4
Disposal Planning 
      The development of plans that prioritize and optimize the disposal of assets         identified as surplus in the "asset review and analysis" process. Source:         L1
 Dispute Resolution Procedure 
      The methods and actions involved in mediating and settling disputes. An alternative         technique for the resolution of a contract dispute by way of independent         third parties rather than court proceedings. Source:         N1 
      An alternative technique for the resolution of contract disputes other than         by arbitration or litigation. It need not involve an independent third         party. Source: S2 
Distributed Database 
      A database with unique components in geographically dispersed locations linked         through a communications network. Source: G1       
Diversity 
      Pertaining to the variety of species within a given association of organisms.         Areas with low diversity are characterized by a few species; often relatively         large numbers of individuals represent each species. Source:         S2 
Downtime 
      That element of time during which a facility, part of a facility, or         an item is not in a condition to perform its intended functions. Source:         N1 
Due Diligence 
      The process of reviewing and analyzing in detail the physical, legal         and financial activities, work processes, agreements, etc. of an existing         service which are relevant to the performance of a future contract for         this service, qualifying risks and establishing strategies to minimize         these risks. Source: T2 
      Can be demonstrated if a responsible person can show that all reasonable measures         were taken to identify and manage a risk to health and safety and financial         considerations. It requires full documentation of all steps undertaken.         Source: S1