ABSTRACT
These terms and definitions are collected and updated from earlier published glossaries [1, 2]. https://www.niso.org/standards/z39-96/ns/oasis-exchange/table">
Term
Definition
Life cycle and life time
Life cycle
The consecutive and inter linked stages of a facility or structure, from the extraction or exploitation of natural resources to the final disposal of all materials as irretrievable wastes or dissipated energy.
Survival life
The time period from the beginning of use until the demolition of a facility.
Working life
The time from the begin of use until the end of the first lifetime period of use, first refurbishment or demolition, usually the equivalent of design life.
Life time
The time from the start of the planning of a building project until a defined point in time, or until the end of its life cycle.
• Life time period
The time from the start of the planning of a facility or construction project until a defined point in time, or between two defined points.
• Design life period
A specified period of time used in design considerations, design calculations and associated decision-making.
• Procurement responsibility period
A specified period defining the responsibility of contractor during the lifetime of a construction project.
• MR&R period
A specified period over which the calculations, optimisations and decision-making in MR&R planning are done.
Serviceability and service life
Serviceability
Capacity of a structure to perform the service functions for which it is designed and used.
Service life
Period of time after installation during which a facility or its parts meet or exceed the performance requirements.
• Target life
Required service life imposed by general rules, the client or the owner of the structure or its parts.
• Characteristic life
A time period exceeded by the service life with a specified probability, usually with 95% probability.
• Design life
Service life used in the design to provide a required probabilistic safety against the target service life. Design life is calculated dividing the characteristic life by the lifetime safety factor. Design service life has to exceed the target service life.
• Reference service life
Service life forecast for a structure under strictly specified environmental loads and conditions for use as a basis for estimating service life.
Service life planning
Preparation of the brief for the structure and its parts in order to achieve control of the usability of structures, and to facilitate maintenance and refurbishment in an optimised way.
Service life design
Preparation of the design of the structure and its parts to achieve the desired design life at the defined reliability level.
Reliability and performance
Performance
Measure by which the structure responses to a certain function.
Performance requirement or performance criterion
Qualitative and quantitative levels of performance required for a critical property of a structure.
Lifetime quality
The capability of the facility to fulfil all the requirements of its owner, user, and society over its specified life time.
Failure
Loss of the ability of a structure or its parts to perform a specified function.
• Durability failure
Exceeding the maximum permitted degradation, or falling below a minimum performance parameter.
Failure probability
The statistical probability of failure occurring.
Risk
Multiplication of the probability of an event such as failure or damage.
Obsolescence
Loss of the ability of an item to perform satisfactorily due to changes in economic, performance, human (safety, health, convenience) or ecological requirements.
Limit state
A specified measure or performance parameter exceeding or falling below a defined value.
• Serviceability limit state
A situation in which conditions of specified service requirement(s) for a structure are no longer being met.
• Ultimate limit state
A state associated with collapse or similar form of failure.
Lifetime safety factor
Coefficient by which the characteristic life is divided to obtain the design life.
Factor method
Modification of reference service life to take account of the specific environmental loads and in-use conditions.
Attribute
A property of an object or its part used in optimisation and selective decision-making between alternatives.
• Multiple attributes
A set of attributes used in optimisation and selective decision-making between alternatives.
Durability
Durability
The capacity of a structure to maintain minimum performance under actual environmental degrading loads.
Durability limit state
Minimum acceptable state of performance or maximum acceptable state of degradation.
Durability model
Mathematical model for calculating degradation, performance or the service life of a structure.
Performance model
Mathematical model showing performance over time.
Condition
Level of critical properties of a structure or its parts, determining its performance ability.
Condition model
Mathematical model for placing an object, module, component or subcomponent in a specific condition class.
Deterioration
The process of becoming impaired in quality or value.
Degradation
Gradual decrease in performance of a material or structure.
Environmental load
Impact of environment on a structure, including weathering (temperature, temperature changes, moisture, moisture changes, solar effects, etc.), chemical and biological factors.
Degradation load
Any combination of environmental and mechanical loads.
Degradation mechanism
The sequence chemical, physical or mechanical changes that lead to detrimental changes in one or more properties of building materials or structures when exposed to degradation loads.
Degradation model
Mathematical model showing degradation over time.
Management and maintenance
Maintenance
Combination of all technical and associated administrative actions during the service life designed to retain a structure in a state in which it can perform its required functions.
Repair
Return of a structure to an acceptable condition by the renewal, replacement or mending of worn, damaged or degraded parts.
Restoration
Actions to bring a structure to its original appearance or state.
Refurbishment or Rehabilitation
Modifications and improvements to an existing structure to bring it up to an acceptable condition.
Renewal
Demolition and rebuilding of an existing object.
M&R
Maintenance, plus repair, restoration, refurbishment and renewal.
Project
Planning and execution of repair, refurbishment, restoration or dismantling of a facility or parts of it.
Life cycle cost
Total cost of a structure throughout its life, including the costs of planning, design, acquisition, operations, maintenance and disposal, less any residual value.
Environmental burden
Any change to the environment which permanently or temporarily results in loss of natural resources or deterioration in the air, water or soil, or loss of biodiversity.
Environmental impact
The consequences for human health, the well-being of flora and fauna, or the future availability of natural resources, attributable to the input and output streams of a system.
Integrated lifetime design of materials and structures
Producing descriptions for structures and their materials, fulfilling the specified requirements of economics, human requirements (safety, health, convenience), ecology (economy of the nature), cultural and social needs, over the life cycle of the structures. Integrated structural design is the synthesis of mechanical design, durability design, physical design and environmental design.
Environmental structural design
That part of the integrated structural design that takes into account environmental aspects during the design process.
Integrated lifetime management
Planning and control procedures in order to optimise economic, human, ecological, cultural and social conditions over the life cycle of a facility.
Hierarchical system
System
An integrated entity which functions in a defined way and whose components have defined relationships and rules between them.
Hierarchical system
A system consisting of some value scale, value system or hierarchy.
Modulated system
A system whose parts or modules are autonomous in terms of performance and internal structure.
Structural system
A system of structural components which fulfil a specified function.
Network
Stock of objects or facilities (e.g. bridges, tunnels, power plants, buildings) under management and maintenance of an owner.
Object
A basic unit of the network serving a specific function.
Module or assembly
A component or set of components designed and manufactured to serve a specific function(s) as part of the system, and whose functional, performance and physical relations with the structural system are specified.
Structural component
A basic unit of the structural system designed and manufactured to serve a specific function(s) as part of a module, and whose functional, performance and physical relations with the structural system are specified.
Subcomponent
Manufactured product forming a part of a component.
Material
A substance that can be used to form products.
Stakeholders
Stakeholders
Owners, users, designers, contractors, industry sectors, public interest organisations, regional interests and/or government agencies connected with the structure during its life cycle.
Owner
Person or organisation for which a structure is constructed, and/or the person or organisation that has the responsibility for the maintenance and upkeep of the structural, mechanical and electrical systems of the building.
Designer
Person or organisation that prepares a design or arranges for any person under one’s control to prepare the design.
Contractor
Person or organisation that undertakes to, or does, carry out or manage construction work. The contractor bids a contract for a new building with information from manufacturers and suppliers. The contractor’s representative on the building site is the site supervisor.
Manager
At takeover, the building is administrated by a property manager who engages maintainers to be responsible for proper maintenance inspections or to carry out the necessary maintenance.
Supplier
Person or organisation that supplies structures, parts of structure
User
Person or organisation which occupies a facility.
Dismantler
Person who carries out dismantling work.
Methods
Allocation
The division of specified financial and physical resources amongst objects, projects and other actions on the network level.
Briefing
Statement of the requirements of a facility.
Service life planning
Preparation of the brief and design for a facility and its parts in order to optimise the required properties of the facility for its owner, and to facilitate maintenance and refurbishment.
Condition assessment
Methodology and methods for quantitative measurement and visual inspection of the properties of an object and its parts, and conclusions drawn from the results regarding to its condition.
Optimisation
Selection between alternative properties of an object or its parts, or of an action taken in order to reach an optimal solution or result.
• Short-term optimisation
Optimisation over a short-time period (usually one or two years).
• Long-term optimisation
Optimisation over a long-term period (usually several or even tens of years).
Decision-making
Methodology for rational choices between alternatives, basing on defined requirements and criteria.
