UNIVERSITY OF NAIROBI DEPARTMENT OF REAL ESTATE AND CONSTRUCTION MANAGEMENT

UNIVERSITY OF NAIROBIDEPARTMENT OF REAL ESTATE AND CONSTRUCTION MANAGEMENT BBE 533: MAINTENANCE MANAGEMENT PAUL M.SYAGGA,PhD MARCH 2010

COURSE OUTLINE FOR BLE 533: MAINTENANCE MANAGEMENT. 1.Principles of maintenance management • What is maintenance? • Facilities management • Nature and types of maintenance 2.Economics of building maintenance • Determinants of maintenance • Design and maintenance • Life cycle costing • Service life prediction 3.Maintenance management process • Condition assessment for maintenance • Prioritization for maintenance • Resource requirements for maintenance • Execution of maintenance works

COURSE OUTLINE FOR BLE 533: MAINTENANCE MANAGEMENT. 4.Building failures diagnosis and avoidance • Causes of defects in buildings • Defects in foundations • Defects in floors and floor finishes • Defects in walls and wall finishes • Defects in roofs and roof coverings • Defects in plumbing and electrical systems • Grounds maintenance 5.Conservation of historical monuments • Need for conservation of monuments • Procedures in conservation of monuments • Laws relating to conservations of monuments in Kenya

1.Principles of maintenance management 1.1.What is maintenance? • The following terms that are often used in property industry in relation maintenance need to be defined to avoid confusion. • Maintenance : refers to work undertaken in order to keep or restore a facility/property to an acceptable standard. • To keep means to maintain to the same or nearly the same physical and functioning level as original. • To restore means to put back to the same or nearly the same original physical and functioning level • Acceptable standard means that physical and functioning level which sustains the utility and value of the utility/property. This is because there is no absolute standard which is satisfactory in all cases all the time. ii. Maintenance management: refers to activities undertaken to make sure that capital investments are protected as well as ensuring acceptable working environment for users, depending on the quality of investment and costs in use. iii. Asset management: refers to the process of creating register of assets,and conserving the assets for the operations of the organisation.Thus creation of data base and property maintenance are components of asset management.

1.Principles of maintenance management contd. iv. Property management: refers to process directed at maintaining the value of property as a resource and includes: • Overseeing physical maintenance • Rental assessment and collection • Enforcement of lease covenants • Advise on whether to maintain,rehabilitate or redevelop v. Conservation: refers to the preservation of facilities including their maintenance so that they may continue serving their useful purpose as well as retaining their historical and cultural features for posterity. vi. Facilities managementy.A new concept in property industry that embraces a wide range of property and user-related functions.It is the active management and co-ordination of non-core building services (buildings,fittings and furniture,plant and equipment,IT,etc) together with associated human resources necessary to assist an organisation achieve its strategic objectives.

1.Principles of maintenance management contd. 1.2.Facilities management • Facility management is an interdisciplinary field primarily devoted to the maintenance and care of commercial or institutional buildings, such as hotels, resorts, schools, office complexes, sports arenas or convention centers. Duties may include the care of air conditioning, electric power, plumbing and lighting systems; cleaning; decoration; groundskeeping and security. Some or all of these duties can be assisted by computer programs. These duties can be thought of as non-core or support services, because they are not the primary business (taken in the broadest sense of the word) of the owner organization • The term facility management is similar to property management although not exactly the same.While both manage the day to day operations of a facility/property such as cleaning, maintenance and security, similar to Janitors, one must not confuse it with such a title. • The property manager has an expanded role which includes leasing and marketing activities whereas the facility manager role focuses on existing tenants who usually are owner occupants. • An important feature of facility management is that it takes account of human needs of its tenants in the use of buildings and other constructed facilities. These softer factors complement the harder factors associated with the maintenance and care of engineering services installations.The term "end-user satisfaction" is often used both as a goal and a measure of performance in facilities management.

1.Principles of maintenance management contd. • The discipline of facility management and the role of facility managers in particular are evolving to the extent that many managers have to operate at two levels: strategic-tactical and operational. In the former case, owners need to be informed about the potential impact of their decisions on the provision of space and services. In the latter, it is the role of a facility manager to ensure proper operation of all aspects of a building to create an optimal environment for the occupants to function. • This is accomplished by managing some of the following activities. i)Environmental Health and Safety: Building Cleanliness;Waste Removal;Occupational Health and Safety;Hazardous Material compliance,etc. ii)Mechanical Systems Maintenance including preventive and predictive maintenance of: • HVAC/R (Heating, Ventilating, Air conditioning and Refrigeration) to regulate Indoor Air Quality and Temperature Control; and Elevator Maintenance

1.Principles of maintenance management contd. iii)Power Systems maintenance including • Normal power such as Electrical Substations and Switchgear • Emergency power systems such as Uninterruptible power supply (UPS) systems, and Standby generators iv)Building Systems including Building Automation Systems (BAS),Building Monitoring systems (monitoring capabilities only) and Security and Locks. v)Life/Safety Systems that include Sprinkler systems,Smoke/fire detection systems,Fire Extinguishers; Signage and Evacuation Plans. vi)Space Management including Office Space Layout and Furniture Placement and Systems • In summary typical functions of Facilities Management which can either be outsourced or carried out by a combinationcan of in-house and outsourcing can be summed up as • Facility acquisition whether through development,purchase or lease • Strategic facility space planning,particularly space allocation for people and equipment • Support services such a office administration • Facility operations and maintenance,in particular to achieve equipment availability as well as ,health and safety of users.Thus maintenance though would seem as merely one of the activities of facilities management,it is indeed a major and critical activity performed during the operational phase of a building’s life cycle, which normally extends over many decades. References • International Facility Management Association • British Institute of Facilities Management • Journal of Facilities Management

1.Principles of maintenance management contd. 1.3.Nature and types of maintenance 1.3.1.Purpose of maintenance: primary purpose of maintenance is to preserve, keep or restore a facility/property to its initial state to the extent practicable or to an acceptable standard so that: • It remains in a state that is neither dangerous nor injurious to the health of the occupants i.e. it must maintain health and safety standards for public health • It continues to provide functional utility for which it was intended: as a factory, mosque, hospital, state house, etc) • It retains the value of investment as a capital asset thus continuing to provide adequate return on investment • It presents good appearance: preserving the character of the neighbourhood and enhancing the self-esteem of both owner and occupants, i.e. the way we look is not very different from what we are.

1.Principles of maintenance management contd. 1.3.2.Maintenace activities There are basically three activities that constitute maintenance works namely: • Servicing:day to day routine chores that maintain cleanliness and order • Rectification: making good faults arising from design, unsuitable materials or poor construction • Replacement: restoring some worn out materials or components due to wear and tear or incorrect use • A fourth type of activity often confused with maintenance are any works of a capital nature carried out to improve on the original design or as major overhaul to the original design and specification such as modifications,alterations,renovations,which are improvements to a facility,rather than maintenance.Such works add more than retain the original design.

1.Principles of maintenance management contd. 1.3.3.Types of maintenance The three maintenance activities usually categorised by the manner in which the works are executed namely: • Planned preventive maintenance: work organised and carried out with forethought and intended to reduce the probability of failure or performance degradation namely: • Scheduled maintenance at pre-determined intervals • Condition-based maintenance based on continuous monitoring • Running maintenance carried out when machine is in service • Preventive shut-down maintenance, when factory closes down for maintenance ii. Planned corrective maintenance:work organised and carried out after a failure has occurred i.e. advance provision is made in form of labour and spares so that work is carried out through: • Corrective shut-down maintenance carried out after failure but for which expenditure provision had been made • Emergency corrective maintenance to avoid serious consequences. • Unplanned/emergency/breakdown maintenance: ad-hoc maintenance as a result of unseen or damage due to external sources. It may also described as “wait and see “ maintenance

2.Economic of maintenance . 2.1.Determinants of maintenance • While there may be no absolute standard for all facilities all the time largely on account of economic and social considerations, there ,however, some standards are universally applicable such as structural stability or public health concerns.Thus what is injurious or dangerous to the safety and health of occupants/users of a building or facility should not be in doubt. • However,considerations for upholding investment value, preserving character of the neighbourhood or enhancing esteem of owners and occupants, could perhaps be subject to varying interpretations. • Therefore the determinants of maintenance standards or factors which influence decisions on how to maintain a facility, are complex and sometimes conflicting, and in particular they include the following: • Design factors(acts of omission/commission during design and construction) • Statutory requirements • User requiremets/Type of user • Value considerations • Budgetary constraints

2.Economics of maintenance contd. 2.1.2.Influence of design on maintenance • Any building/facility is designed to satisfy the functional requirements for utility, aesthetics, and user-friendliness. • However, the need for maintenance arises either from normal wear and tear or defects of omissions/commissions during design, choice of construction materials/components, construction phase, and the use/abuse during occupation. • Informed design should draw a balance between functional requirements and the overall financial commitments(initial and maintenance costs) throughout the life cyle of the building/facility. • There exists an inverse relationship between initial costs(purchase/construction) and future maintenance costs, so that a reduction in future maintenance costs may be obtained by increasing initial costs and vice-versa. • The problem is to determine the optimal model for the inter-relationship of initial and future costs of a development project at the design stage. A technique often used in this determination is called life-cyle costing. • See figure on “Effects of early design decisions on building life-cycle costs” in Syagga and Aligula(1999) page 50.

2.Economics of maintenance contd. 2.1.2.Statutory requirements Some legislation may prescribe standards of safety or hygiene to achieved in the management of assets notably, lifts and fire equipment, preservation of monuments or structural safety of buildings. For example: • Antiquities and Monuments Act(1983) prescribe that no person is allowed to destroy, alter or deface monuments or do any work that would impair the preservation of monuments, nor extend or modify the external of the monument. • Public Health Act requires that buildings are constructed and maintained in such a manner that they are neither injurious nor dangerous to health of dwellers; nor dilapidated/ defective as to be unsafe. • Registered Lands Act(1963)(section55), states that “to keep a building in repair”,shall in the absence of express provision to the contrary mean “in such a state of repairs in which a prudent owner might reasonably be expected to keep his property due allowance being made for age, character and locality of the building at the commencement of the lease” • Other pieces of legislation that make reference to property maintenance include Occupational Safety and Health Act(2007),Local Government Act(Revised 1998),Sectional Properties Act(1987),laws relating to landlords and tenants,etc .

2.Economics of maintenance contd.. 2.1.3. Basic user requirements • These include the provision of shelter from weather and provision of acceptable indoor environmental conditions. These may be realized through the three levels of care: basic level, intermediate, and intensive/highest level of care. • However, sometimes user requirements go beyond what was originally designed, in which case they call for improvements rather than maintenance, as for instance, new facilities are added. • User requirements will also depend on the type of facility and status symbol, such that maintaining a classroom is relatively less demanding than maintaining a hospital ward, a presidential suite in a hotel or the state house grounds.Similarly,maintenance level of a life support equipment is certainly higher than any other equipment in a hospital. The concept of duty of care: • Like a hospital patient a building or other facility requires varying levels of attention through out its economic life, notably • basic care: cleaning/servicing, • intermediate level of care:inspections and repairs, and • intensive care:replacements/renewals of components. • The needs can be determined at the design stage,then subsequently monitored and re-appraised regularly when the building is in use, and appropriate level of attention given so that the building can continue to fulfill its functions. • The concept of duty of care marries in well with planned preventive maintenance • See figure on “Levels of maintenance in the context of duty of care”

2.Economics of maintenance contd.. 2.1.4.Value considerations • Properties that are tradeable in the market require some minimum level of maintenance for them to attract market value. • The optimum level of expenditure on maintenance should be that which gives maximum return, i.e. point at which marginal increase in maintenance expenditure equals marginal value(dv/dm=1). • For properties which do not trade in the market the marginal value is synonymous with utility/functional value. The appearance of a building must be acceptable in terms of culture,religion,defence or status. • The way things look is not irrelevant to the way things work: how they look is how they should look. The concept of obsolescence. • Abuildingor other facility has three types of life:the physical life; the functional life; and the economic life that need to be preserved so as to avoid negative/reducing effect called depreciation. • Depreciation on physical life of a building arising from wear and tear or physical impact is called physical depreciation • Depreciation on the functional life of a building, arising from errors/omissions in design(room sizes,ceiling heights,facilities/amenities) is called functional obsolescence., and is regarde as curable obsolescence.Works carried out to achieve desired standards are called improvements or rehabilitation. • The depreciation/loss in value arising from conditions external to facility that affect its character/degree of utilisation, hence less demand (presence of a nuisance,outmigration,economic downturn)is called economic obsolesence, and regarded as incurable obsolescence. It cannot be corrected through maintenance,except by demolition or change of user. • Obsolescence sometimes in depreciation when it precipitates physical deteroriation because when demand falls property gets neglected and suffers severe physical deteroriation leading to demolition

2.Economics of maintenance contd.. The present value concept: • Economic obsolescence is incurable,but physical and functional obsolescence can be cured through maintenance and rehabilitation, respectively.Rehabilitation involves conversion and modernisation beyond the routine maintenance. • However,with time it may be necessary to consider whether to continue to maintain,rehabilitate or demolish a building or facility. The decision is normally made in favour of higher present value of proposed development. • The comparison is made between modernisation and replacement with a new facility on the same site, with both values being discounted to the present value. • Present Value,Y is denoted by Y=1/(1+i)^n, where”I” represents the interest/discount rate, and “n” represents period by which the rehabilitation/redevelopment will be realised/mature.

2.Economics of maintenance contd.. 2.1.5.Budgetary constraints • In industry,the responsibility of maintenance is to ensure that the facilities/equipment used in production are operating at the required level of productive efficiency and are available when required. • Thus inadequate maintenance would not only lead to costly repairs but to lost production as well. • Optimum equipment availability is achieved when the total sum of maintenance costs(preventive + corrective) is at minimum. • When less preventive maintenance is applied breakdown maintenance increases and equipment availability reduces.It is therefore possible to reduce breakdown costs and increase equipment availability by increasing preventive maintenance upto a point when the sum of the two is at minimum, and that becomes the optimal point. • Thus equipment availability(operating level of efficiency when required) may determine how much maintenance is necessary and what to spend on the same, this being where the total sum of the two is at minimum.

2.Economics of maintenance contd.. 2.2.Life cycle costing • Life cycle costing is a tool to be used in the decision-making process, the objective being to ensure the best value for money over the economic lifespan of the asset with the time value of money being taken into account. • It is comparative evaluation of time-phased costs(total/whole life costs) and revenues attributable to a project/asset/component over a specified project life.The total /whole life cycle cost of the asset is the sum of initial acquisition costs and subsequent running costs of an asset over its operating life. • It is also known as whole life-cycle costing,cost-in use,engineering economics,cost-benefit study or terotechnology. • The process contains parallel and inter-related phases namely: • Establish the objective and justification for the project • Identify the life-cycle/total/whole costs likely to occur in the life of the project • Formulate assumptions to be employed in the analysis(lifespan,discount rates,frequency/incidence of life costs,etc • Rank the alternative cost scenario using any comparative methods of analysis including NPV,IRR, Annual Equivalent(AE),Payback period,etc. • Subject the results to further sensitivity analysis to the various cost factors so as to rationalise acceptable alternative • See Fig on Key Decisions in the Whole Life-cycle costing Process of a building facility.

2.Economics of maintenance contd. 2.3.Service life prediction 2.3.1.Need for service life prediction • The need for “Sustainable Construction” necessarily imposes inherent requirements for specified levels of durability of building materials and components and it is understood that these can only be entrenched within the construction sector through standardization. • Standards,including practices and guidelines for predicting service life would support the performance approach by facilitating evaluation of long-term performance(durability performance) of both new and traditional materials and components in their intended service environments. • Service life prediction is a requisite tool for helping assess long-term environmental effects,for maintenance management of infrastructure systems,or indeed for maintenance of building envelop systems,envelope components and related materials. • Increasingly building material and component manufacturers are seeking sytematic methods to assess the likely risk of premature deteroriation of existing products given specific climatic effects,or the most vulnerable exposure conditions of new products in specified systems. • Ability to predict the service life of building materials,components,and systems is needed to improve the selection processes.Because durability is a vague term,evaluation of durability using existing standards does not give adequate service life information.

2.Economics of maintenance contd. 2.3.2.Durability testing and service life testing compared. • In Kenya both the Kenya Bureau of Standards and the Materials Branch of the Ministry of Roads and Public Works undertake durability tests on building materials with respect to the following parameters/attributes. • Dimensional measurement • Compressive strength • Water-absorption and moisture content • Density • Weathering • Rupture • Fire resistance • Thermal conductivity • Noise attenuation

2.Economics of maintenance contd. • One needs to note ,however,that the above typical standard durability tests cannot provide useful service life information because: • Each standard is developed as a screening test and employs a single arbitrary set of severe conditions intended to cause the same mode of failure as that expected in service, and • The relationship between the laboratory exposure conditions and expected service conditions is not known. • What is really needed is an approach that yields information about the individual and combined effects on service life of differences in material,processing,design,exposure and application variables. • In contrast to the typical durability test, service life prediction requires definition of one or more failure criteria,characterisation of service conditions,determination of rates of degradative reactions in many specimens under conditions which can be related to those expected in service,and calculations of times of failure and their distribution. • Because a reliability approach is clearly preferred,service life prediction tends to be data-intensive both in the amount of data that should be collected and that which should be available in databases. • A standard durability test can usually be performed by a technician with little supervision,whereas service life prediction requires experiments planned,supervised,and analysed by a materials specialist.As a result,a service life prediction standard is different from a typical durability standard. • The problems of service life prediction tend to increase in difficulty with the number of materials in a building component,largely because of the increased number of interfaces between dissimilar materials; the difficulties increase even more with systems consisting of many components.

2.Economics of maintenance contd.. 2.3.3. Service life prediction standards • There are currently a number of ISO 15686 standards on service life prediction based on the works of ASTM,RILEM,CIB and others namely: • ISO(2000) 15686-1:Part 1 on General Principles describes the general principles and procedures that apply to design,when planning service life of buildings and constructed assets.It is important that the design stage includes systematic consideration of local conditions to ensure,with a high degree of probability,that the service life will be no less than the design life.The standard is applicable to both new constructions and the refurbishment of existing structures. • ISO(2001a) 15686-2: Part 2 on Service Life Prediction Procedures describes methodology/procedure that facilitates service life predictions on building components. • ISO(2002) 15686-3:Part 3 on Performance Audits and Reviews is concerned with ensuring the effective implementation of service life planning.It describes the approach and procedures to be applied to pre-briefing,briefing,design,and construction,and where required,the life care management and disposal of buildings and constructed assets to provide a reasonable assurance that measures necessary to achieve a satisfactory performance over time will be implemented. • ASTM = American Siciety for Testing and Materials • RILEM = International Union of Testing and Research Laboratories for Materials and Structures • CIB = International Council for Building Research Studies and Documentation

2.Economics of maintenance contd.. • The above standards are procedural and premised on the assumption that for each building component or product there is a reference service life(RSLC) that can be adjusted by factors(environmental load,material quality,wormanship,and other related factors)describing deviations from the reference situation to the actual building conditions.This permits reaching an adjusted service life estimate(ESLC) for the component or product that is then used in estimating the service life of the building or the component. • One key concern is the determination of what the Reference Service Life(RSLC) of a product or component is prior to using the factor method. • The RSLC is the service life that a building or component would expect or is predicted to have(ESLC) in a certain set(reference set) of in-use conditions.Thus ESLC=RSLC*A*B*C…(factors); for which A,B,C….=/<1(equal to or less than 1). • This factorial approach(“factor method”) need further development and refinement as regards the factors,the theoretical calculation methods,and the reference life data to be used. • It is in effect a method by which to transfer knowledge on service life from a known reference condition to a project specific condition and is typically used in engineering design.

2.Economics of maintenance contd.. 2.3.4.Methods for the development of RSLC • The development of RSLC is guided by two fundamental questions namely: • What standards are required(what are the aspects/factors of durability and performance)? • How are these standards to be determined/established? 2.3.4.1.Requisite RSLC standards • Determination of mechanical and environmental loads(in laboratory tests and in real service,real and simulated) to which materials or components are likely to be subjected • Characterisation(macro,micro and surface) of materials and components • Identification of degradation of kinetics of materials and components (in different environments and at different locations in the specimen,taking size effects,surface effects,and effects of flaws into account) • Identification and expression of performance requirements and performance criteria for materials and components • Organization and representation of computerized knowledge of materials and components.

2.Economics of maintenance contd. 2.3.4.2.Approaches to determination of RSLC • The current primary approaches and methods for evaluating the service life of a building component include the following six methods, which also describe their main usage: 1) Methods based on a probabilistic approach (Sierres et al. 1985); these are currently used, for example, as the basis for standards and guidelines regarding structural design calculations. 2) Statistical approaches (Brandt and Wittchen 1999) that may be used when data on several equivalent building components are available.(3) Comparisons between long-term and short-term exposure tests (Jernberg et al. 2004), typically a standard practice for the treatment of the results derived from laboratory and in-service tests. (4) Feedback from practice, which is considered a standard practice for the diagnosis of a building component failure. (5) Factorial method for service-life estimation,for which there exist several formulations and associated research, is synthesized i)Relating to or being an instrument whose sound is modified or augmented by a synthesizer.Ii)Relating to or being compositions or a composition performed on synthesizers or synthesized instruments. in Jernberg et al. (2004). This method is commonly used for the assessment of the service life of in-service building components and in-service buildings. The factor method is a standard method given in ISO 15686. (3) (6) Methods based on possibility theory (data fusion) as detailed in Lair (2000) and Jernberg et al. (2004).

2.Economics of maintenance contd. • The probabilistic approaches are well adapted when the studied phenomenon is well known; that is to say, when enough information is available to define the relevant probability law and its parameters. Several probability laws are well known and well fitted to the more common degradation phenomena of classical materials in civil engineering. However, the definition of the probability law and its parameters is difficult when a complex building component is studied and when no or only a small amount of information is available, which is the usual case in the construction domain. • The statistical approaches are well adapted when sufficient observations of a specific building component are available, such that a coherent sample can be done and statistical principles can be applied. However, even if in some civil engineering domains such statistics exist (for example, road, dams, and railways), this is not a current practice in the building domain. • The first four methods and approaches have two primary similarities: i) They proceed to a direct assessment of service life, that is to say, the service life of a building component can be determined from the use of probability functions, statistics, tests results or inspection results relevant to this specific building component. For example, if considering a statistical approach, the service life of a window unit can be deduced from the observation of the behaviour or response of the unit over time of a set of similar window units.(ii) It is difficult to transpose/transfer their results to other related inservice environments and to other building components. For example, the results of an accelerated short-term exposure test of a rubber component subjected to ultraviolet radiation cannot be used to evaluate the service life of this same type of rubber component when exposed to freeze-thaw conditions

2.Economics of maintenance contd. • The fifth method (factorial method) proposes a direct assessment of service life and permits taking into account the specific effect of each in-service condition. However, a significant drawback of this method is the subjective manner in which the factor values are estimated. • The last method (data fusion) for determining the service life of building components, proposed by Lair (2000), allows a direct assessment of the component. Hence, the main focus is to further develop this method for other types of data (service life, probability, and performance data) and at other geometrical levels (material, element, and building component). • If the primary objective is to be able to assess the in-service service life of all geometrical entities (from materials to building) considering all their possible degradation scenarios and functions (as mechanical resistance, thermal isolation or esthetical function,...). Among existing approaches, the approach based on possibility theory is the only one to allow this objective to be reached.

2.Economics of maintenance contd. 2.3.4.3. Steps in the determination of RSLC The proposed methodology allows one to duduce the service life of building components, i.e., the time to reach the multi-performance profile that corresponds to the failure of the building component.The methodology is comprised of four primary steps: i) Undertaking a system analysis to provide an overview of the functioning of the building component, which is indispensable to complete an FMEA. ii) Identification of all possible degradation scenarios of the building components as well as their causes and consequences using failure mode and effects analysis(FMEA). iii)Collection and preparation of RSLC data (service life, probability, and performance) associated with the degradation scenarios,transformation of this data into a fuzzy-set format, and assessment of its quality; . iv)Service-life assessment.

2.Economics of maintenance contd. • System analysis • A system analysis requires modeling the behaviour of the building component when subjected to environmental stresses (climatic and usage) over its in-service stage. It is from this stage that a "functional model" of the building component of interest can be developed; such a model provides a means to link actions causing deterioration to that of loss in functional performance and is a prerequisite for carrying out the FMEA . • The first step of this analysis is to build an organisational model. This requires assessing the mechanical, physical, and chemical characteristics of the individual elements of which the building component is comprised and the respective geometrical scales in which these elements are constituted, and then determining the interrelation among all elements. • In a second step, the environmental stresses that may cause degradation of the building component are characterized; this step includes first determining the environments to which the building component may be subjected. For example, establishing the environments that exist on the interior and exterior surface of a wall. • Then, the environmental agents that may cause degradation of the building component are identified (e.g., snow, wind, solar radiation, etc.). • The final step is to develop a "functional model" based on the identification of performance functions that are characteristic of the building component and its elements. This permits an understanding of the building component behaviour in terms of its functional performance when subjected to the previously defined stresses.

2.Economics of maintenance contd. 2. Failure mode and effects analysis(FMEA) • The purpose for completing the FMEA is to obtain as complete a list as possible of degradation scenarios or chains of degradation that could damage the building component during the in-service stage. The FMEA is a risk analysis method, developed during the 1970s and still being used in different industrial fields, such as the spatial, nuclear, and medical fields (Dyadem Press 2003). The application of this method to the building field was initiated by Lair (2000), who modified the chaining of the analysis that now allows the analysis to benefit from the results of FMEA. • The first step in applying the principles of FMEA consists of defining the potential degradation modes, the causes (stresses, incompatibilities between materials, errors during building construction), and the consequences for each function, component. • The second step consists of determining the degradation scenarios in an iterative .The iterative principle, from step i (step i = 0: beginning of the in-service stage) to step i+ 1, aims to determine if the degradation consequences at step i could be the cause of degradation at step i + 1.

2.Economics of maintenance contd. 3.Collection and preparation of RSLC data The collection and preparation of data(service life, probability, and performance related) is an important step in the methodology that is summarized here.All available data useful to the service-life assessment and that may be derived from different sources of information are collected and organised in the following manner: • service life of each set of scenarios, each single scenario, and each single phenomenon that have been identified from the previous step of the methodology; • the probability of occurrence of each set of scenarios, each single scenario, and each phenomenon, which have been determined in order to deduce the most probable scenarios to be considered for the service-life assessment; • performance versus degradation functions of each pair, {phenomenon; function}, that have been identified from the FMEA and that allow deducing the multiperformance profile of the building component from the knowledge of the degradation states of its elements. • Given that these data may be obtained from several sources, they may be heterogeneous, imprecise, uncertain, and incomplete in nature. It is for this reason that the quality of each piece of data must also be evaluated.If the quality of the data at the objective point is not sufficient, then it is necessary to obtain available data at other points.

2.Economics of maintenance contd. 4. Service-life assessment • The set of principle outputs of this last step of the service-life assessment methodology include the following: (i) to assess the service life of the entire set of scenarios of the building component, without considering their probability of occurrence; (ii) to assess the probability of occurrence of each scenario to retain only the more probable ones in the pursuit of the methodology; (iii) to deduce the multi-performance profile at a specified time in the life of the building from the duration of the retained scenarios, based on the outputs derived from the performance versus degradation functions. • Finally, the service life of the building component is obtained when the multiperformance profile corresponds to the failure profile; that is to say, when the performance level of one function or a combination of functions reaches its failure threshold. • This approach is rather similar to the life-cycle optimization that uses a probabilistic approach ,except that: (i) an approach based on possibility theory is proposed; (ii) all the possible degradation scenarios of the consider entity (material, element, building component) are taken into account; (iii) several types of functions, such as mechanical resistance with thermal and acoustical isolations, are managed together.

2.Economics of maintenance contd References: • Durability of Building Materials and Components by Seda and Levitan,1980 • Durability of Building Materials and Components by Baker P.J et al,1990 • Guidelines on Durability in Buildings by Canadian Standards Association,1994 • Guide to Durability of Buildings, and Building Elements,Products and Components by British Standards Institution,1992. • ISO 15686(1,2,3&8) on Building and Constructed Assets • Failure mode and effects analysis in the cladding industry(Layzell J. P.1997), International Conference on Building Envelope Systems and Technology, ICBEST’ 97, Bath, UK (April 1997), pp. 85-90 • Durability assessment of building systems(Lair, J. and J-F. Le Teno,1999), in: Durability of Building Materials and Components 8, M. A. Lacasse and D. J. Vanier, Eds., Proceedings of the 8th International Conference on the Durability of Building Materials and Components, Vancouver, Canada (June), pp.1299-1308. • Failure Mode Effects and Criticality Analysis (FMEA) – a tool for risk analysis and maintenance planning(Lair, J.,2003)).Report submitted to the CIB W80/RILEM 175-SLM Service Life Methodologies, February, CSTB France.

3.Maintenance management process • 3.Maintenance management process • Condition assessment for maintenance • Prioritization for maintenance • Resource requirements for maintenance • Execution of maintenance works

3.Maintenance management process 3.1.Condition assessment for maintenance • Effective building maintenance requires the following information in order to retain or restore the same to the desired condition,which in turn primarily determine the cost and timing of maintenance work. • Applicable condition standards:acceptable standards for each category of building • The condition of the building fabric,elements,etc • The frequency of failures • The type and extent of maintenance work required • The risks associated with postponement of the required maintenance work • The quality of the building fabric or elements for use.

3.Maintenance management process contd. 3.1.1.Condition standards • Queensland Department of Public Works in Australia for instance,uses the following five levels of rating to determine maintenance standards for each building or equipment: • Level 5:bestpossible condition for buildings/equipment with highly sensitive functions(operating theatres, steam plant and medical gas in hospitals) or high profile buildings(parliament or state house,etc) • Level 4: good operational and aesthetic condition for good public presentation and high reliability and functionality such as five star hotels,embassies,banks; or water treatment plants, standby generators in hotels and hospitals • Level 3: reasonable condition to meet operational requirements, such as school buildings or lifts. • Level 2: minimum condition to meet minimum operational and safety and health requirements only, such as car ports, storage facilities; garden irrigation systems,etc • Level 1:holding condition for dormant assets to be maintained at minimum to meet statutory requirements pending disposal/ demolition.

3.Maintenance management process contd. 3.1.2.Condition and risk assessment The quantification of maintenance demand is governed by the need to define the gap between current and the desired condition.The process takes the following steps: • Assessment of defects: diagnose the defect and ist causes • Assessment of remedial action:based on the diagnosis of the defect and cause,proposals should be made for appropriate remedial action • Assessment of consequential events if remedial action is delayed:deferred remedial action may lead to further deteroriation and consequential damage to the property • Assessment of the impact consequential event:impact/seriousness of the consequential event/damage as a result of remedial action being deferred • Assessment of the probability of the consequential event occuring:what are the chances that damage may result? • Assessment of frequency of failures:interval between failures,despite remedial action or regular maintenace.This helps in strategic planning process and effective allocation of resources • Assessment of maintenance required:this is not the same as building condition because similar buildings under different conditions could require different degrees of maintenance,and similarly,different buildings under different conditions could have different maintenance needs.

3.Maintenance management process contd. 3.1.3.Rating/assessment of the impact of consequential events • The impact of consequential events if work is postponed may be described in five categories namely: • Catastrophic : postponement may lead to loss of life,structural collapse or exposure to life threatening situations,so that remedial works must be treated as emergency and executed immediately. • Serious:may lead to collapse of major sections with potential health, safety and life risks.Remedial works must be done as soon as possible within 3 to 6 months. • Moderate: substantial detrimental impact on assets/sorrounding assets with potential exposure to health and safety risks,or failure of asset.Work to be done within 12 months. • Limited: limited detrimental impact on the asset/sorrounding assets with limited potential exposure to health and safety risks or failure.Remedial works should be carried out within 24 months. • Negligible:very little detrimental impact on the condition of the asset/soorounding assets. Remedial work can be deferred for more than 5 years.

3.Maintenance management process contd. 3.3.3. Probability of consequential events occurring • The likelihood of consequential event occurring can also be measured on a probability scale so as help in prioritisation of the works a s follows: • Almost certain: it is almost 100% sure(>90%) that the event will occur • Likely:the chance of event occurring is about 80%(>70<90%) • Average: there is about 50% chance that the event will occur(>30<70%) • Unlikely:there is about 20% chance like the scattered thunder showers • Highly unlikely: less than 10% chance,e.g. snow in Nairobi.

3.Maintenance management process contd. 3.2.Prioritization for maintenance • When funds are not enough to carry out all required works some works may be postponed to the next period that funds are available. • The process of assessing the urgency of the required maintenance and ranking the work is called prioritising maintenance work. • The process should be unbiased,objective and take into account as many factors as possible which affect the importance and urgency of the required maintenance works. 3.2.1.Factors determiningin priority rating • The following factors affect/determine the urgency of required maintenance actions: • Risk associated with postponement • The condition of the asset • The frequency of failure • Relative importance of facility/space/element relative to others • Required maintenance action(complexity of the works: replace, repair, service, repaint,remove,clean,etc) • Required quantity of work

3.Maintenance management process contd. 3.2.2.Priority rating system • A more unbiased and objective method is to weigh and rank the priorities according to their urgency as follows: • Identify technical factors affecting the required urgency of required work • Allocate a weight to each factor according to its impact on the urgency of the required maintenance work • Calculate and rank the cumulative weight of all factors affecting the urgency of the required work for each asset/element. • The highest weight is ranked first so that priority 1 is most urgent • The following equation can be used to calculate the priority weight: • P=f(Pr+Pc+Pb+Pf+Ps+Pa)*Cest • Where P= priority weight;Pr=risk factor;Pc=condition factor;Pb=frequency of failures factor;Pf=facility factor;Ps=section factor;Pa=action factor; and Cest=estimated cost required

3.Maintenance management process contd. 3.3.Resource requirements for maintenance Maintenance works can be undertaken in-house or outsourced or a combination of both. Whatever the case, it is necessary that the following cost items are used to determine the financial annual estimates for maintenance: a)Material budget: costing is spread over the various trades in proportion to estimated volume of material usage per trade or activity. b)Plant and equipment budget: based on purchase, hire and the maintenance c)Manpower budget: • Based on estimates of workload on routine maintenance, workload on repairs, work content and resultant productive standard hours(PSH) per job, and effective performance(EP) of the labour force for each trade(productive standard hours/gross hours worked*100). • Based on above, labour required can be calculated as: N=j*wc*100/ep+sc • Where N=number of persons; j =estimated number of jobs; wc=work content per job; ep=effective performance; sc= % of sickness/leave • Total cost of labour force= (Basic wage*N)+% for overhead and other costs(usually being ,1/3 of basic wage). d) Where work is outsourced, it may be based on term contracts with agreed annual rates for labour, materials and equipment, particularly for routine maintenance. For major repair works, bills of quantities may be prepared as needs arise.

3.Maintenance management process 3.4.Execution of maintenance works 3.4.1.Programming • To obtain best possible results with cost effectiveness the work should be programmed according to content, urgency, etc and then translated into weekly and monthly schedule and upgraded regularly. • The following should be considered: • Jobs should be pre-inspected by supervisor so that jobs are allocated to those who can do them best • Plants, tools, equipment and materials must be available at work place when required • Transport must be available to convey operatives to the sites without delay • The operative must spend maximum amount of time during working hours on productive activities • The supervisor must be available to give assistance and advice to operatives when required • A weekly record of accomplishment should be kept and made available to the management

3.Maintenance management process contd. 3.4.2.Performance improvementa) Repairs and maintenance are generally labour intensive,oftenscattered and difficult tosupervise.It is therefore essential to achieve good labour relations with the operatives,and set realistic targets rather than to wield a big stick to the operatives.Thus the supervisor must work with the people, get on with the people and inspire them. b) The management on the other hand,should understand the objectives of the organisation,decide on the target requirements, and monitor the performance achieved in both production and costs. c) The maintenance manager should call a weekly meeting of his management team comprising of appropriate senior staff so as to evaluate the achievements for the week; consider proposals for improvements; and decide on wayforward for the coming week to overcome problems which have been identified as affecting performance. d) Performances monitoring should consider the following in actions to be taken: i)monthly expenditure on labour ,transport and materials against approved budget ; ii)effective performance :lost time,unmeasured work,non-productive work iii)cost effectiveness: depends on effective performance and materials costs iv)work programmes: monitored and compared with objectives v)technical inspections against inspection schedules.

3.Maintenance management process contd. 3.4.3.Maintenance management system(MMS)With advancement in technology, property industry has developed building management system(BMS) for the control of various activities within a building. • A building management system is a computer-based system that links the various systems in a building such as lighting control, air conditioning, access control, public address systems, smoke and fire alarms. This allows intelligence responses to threats or failures to be coordinated across different services. • Various commercial software packages for building management exist such as ARCHIBUS/FM software which is a system of integrated modules with all aspects relevant in the management of a facility: asset register, property leases, security, space occupancy, and maintenance. • Maintenance management system(MMS) is a computer-based system that can be operated separately or as part of a building management system that automates repetitive tasks and structures maintenance flow to suit virtually every operation.

3.Maintenance management process contd. 3.4.4.Tasks included in the MMS Typical automated tasks handled by computerised maintenance management system includes the following activities: • Asset register • Equipment history • Resource allocation • Work order control • Preventive maintenance • Corrective maintenance • Failure reports • Purchasing and inventory control • Supplier tracking • Maintenance cost analysis • Comprehensive management reporting

UNIVERSITY OF NAIROBI DEPARTMENT OF REAL ESTATE AND CONSTRUCTION MANAGEMENT