1 Introduction

Every construction project goes through a lifecycle of different phases, from planning, design, construction, and operation [1]. The facility manager (FM) is responsible for overseeing and managing all facility security, operation, and maintenance tasks to ensure public welfare, health, safety, and facilities operational efficiency [2]. Unfortunately, some clients, contractors, and even engineers disvalue the operation phase or have a misleading background about the FM’s important role and responsibilities. The FM has multiple responsibilities that can only be achieved through the FM’s effective involvement in the project in all four phases which are usually overlooked. Often projects are planned and designed without the FM’s consultancy, which results in multiple long-term problems that could easily be avoided. The facility handover and commissioning to the FMs occur within the operation phase of the building’s life cycle; therefore, the structure is inherited without proper consideration of constant operational efficiencies or functionality, which significantly affects the project's overall cost-effectiveness [3]. The integration of operability, maintainability, and constructability within construction projects would yield numerous advantages and positive outcomes [4, 5]. The integration of facility managers and maintainability aspects into construction projects is an area that has received increasing attention in recent years [6, 7]. In a recent development in 2022 aimed at reducing public expenditures for public projects, the Saudi government’s Expenditures and Projects Efficiency Authority (EXPRO) introduced the National Manual of Assets and Facilities Management. This manual delineates the prerequisites for facility management (FM) involvement during the initial project phases, thereby ensuring optimal operability and maintenance outcomes throughout the entire asset lifecycle for new construction or refurbishment projects [8].

Research proposed a comprehensive framework that addresses the involvement of operation and maintenance contractors during the design and implementation phases of infrastructure projects which facilitates a deeper comprehension of project requirements for researchers [9]. Further study presented a more specialized framework designed to enhance architectural design decisions and practices, encompassing the identification and exploration of problem factors affecting building maintainability within the context of the Turkish building sector, while also formulating strategies to overcome the current shortcomings and foster improved building maintainability in the sector [10]. Research on 35 elevator maintenance issues resulting from design flaws in healthcare facilities in Saudi Arabia emphasized that early consideration of elevator maintainability during the design process can effectively identify potential maintenance problems in later stages and mitigate costs by preventing design choices that lead to future maintenance expenses [11]. Other studies focusing on healthcare facilities in Malaysia corroborate these findings, asserting that proactive measures taken by construction and maintenance teams can help avert numerous building defects, given that a significant portion of the building maintenance budget is allocated to preventing or rectifying such defects [12, 13]. Analysis of 39,093 work orders from a US Air Force Computerized Maintenance Management System (CMMS) unveiled prevalent dormitory facility defects, their associated costs, and the influence of preventative maintenance, potentially inspiring owners, designers, and FMs to integrate maintainability in the early planning and design phases, leading to decreased overall life-cycle costs of the facility [14]. Studies proved that integration of FM during early project phases reduces the facility's annual operational expenses by roughly 20% [15]. In the context of high-rise buildings, a survey identified 42 design deficiencies and 11 mitigation measures aimed at reducing their impact. The analysis indicated that architectural design deficiencies had the most substantial influence on increasing maintenance costs [16].

A case study-based design for maintainability (DFM) guideline was developed in another study to help clients, designers, and contractors during the design, installation, and maintenance of high-rise building facades in tropical areas [17].

Several research gaps still exist in the field of FM involvement in construction. There is a need to define the FM roles and responsibilities in construction projects. This includes understanding their involvement at different project stages, their interaction with other project stakeholders, and the specific tasks they should perform during the project lifecycle. The purpose of this research is to identify the role of FMs during the development stages of construction projects and have a comprehensive view of the potential influence of involving FMs in the decision-making process through the entire project lifecycle. This includes FM roles and responsibilities during planning, design, and construction or execution all the way to operation. This study demonstrates the FM value in construction projects to all stakeholders, including clients, consultants, contractors, architects, and engineers working in the construction industry of Saudi Arabia. This paper suggests how to improve facility operation performances and facility management knowledge. The study introduces a project model to effectively integrate FM during critical project milestones without compromising project administrative integrity.

2 Material and methods

2.1 Approach and methods

This study adopted a rigorous approach aligned with positivism. Employing a deductive approach, the authors designed a research method to gather objective data and assess the validity of the hypothesis. Researchers began with established knowledge about FM roles in projects before the operation phase, forming a general theory. From this theory, the study then derived a specific hypothesis to be tested. This approach allowed for a controlled investigation aimed at uncovering causal relationships within the phenomenon under study [18, 19]. The study applied a quantitative approach and statistical analysis to interpret the collected data and establish interrelationships between measurable dependent variables [20].

2.2 Procedure

First, the study prepared the data collection forms to investigate population opinions. The survey then is sent for data collection and distributed through the cloud data collection software. The study then analyzed the collected data using a Microsoft Excel Analysis tool to yield the results. After the analysis is complete, the study categorizes and reviews the data and results. This step aimed to illustrate and prescribe the relationship between the data and results for item categories with the sample group based on occupational jurisdiction (Client or Owner, Consultant, or Contractor). This allowed the discussion to include each group's opinion on every item category related to each phase and the impact on public health. The illustrated information from the previous phase helps develop an understanding of the FM's responsibilities. The information allows the study of each category's opinion on all phases and discusses the potential reasons behind their perceptions. The questionnaire's collected data is used to measure and evaluate the people's knowledge (working in the construction field in both public and private sectors) of the facility management concept, roles, and application consequences on all project phases. The final part highlights the efforts to fulfill research and establish a model that properly elaborates on the critical FM roles in a construction project.

2.3 Data collection and sampling

The data was collected through a cross-sectional survey which provides a cost-effective means to gather data from a diverse population of different groups at a single time point, facilitating efficient exploration of relationships and patterns [21]. The questionnaires consisted of multiple items grouped into sections based on the project phases (planning, design, and execution), allowing easier data categorization and discussion. Three items group represent FM roles during planning, design, and construction. The first group of items discusses the FM involvement notions during the planning phase including studying project objectives, function, scope of work, budget, feasibility, location, and human resources management plan. The second group discussed the FM's potential roles during the design phase. The items included roles regarding coordination between design and Facility Management departments, architectural design quality and operational efficiency, review of design drawings and loads study, design of firefighting systems, studying user’s behavior and transition in the facility, preparation of tender specifications, selection of materials characteristics, and quantity/costs estimation. The third groups relate to facility management roles regarding the construction/execution phase which discusses contractors' selection in public or private projects, studying change orders, evaluating works during execution, and reviewing compliance of As-built drawings with the execution, handover, and commissioning of the facility. The data had to represent both the facility management and construction management fields. Therefore, the sample included engineers with various occupational responsibilities. In addition, the study applied stratified sampling to ensure that the sample proportionally represents all project stakeholders; hence, engineers of various jurisdictions, including owners, consultants, and contractors of construction and maintenance fields [22].

2.4 Data testing and analysis

The analysis theory applies statistical equations and modeling as a tool to measure the importance of each item. The analysis applies the Relative Importance Index as shown in Eq. (1). The Relative Importance Index in surveys quantifies the hierarchical significance of multiple variables within a dataset, offering a valuable tool for prioritizing factors influencing a given outcome [23, 24]. The influence measured for each item would form the basis of the discussion and recommendations.

$$\text{Relative Importance Index}= \frac{\sum \text{w}}{\text{AN}}=\frac{1 {\text{n}}_{1}+2 {\text{n}}_{2}+3 {\text{n}}_{3}+4 {\text{n}}_{4}+5 {\text{n}}_{5}}{5\text{N}},$$
(1)

where: w is response score, n1 is No. responses of no impact, n2 is No. responses of negligible impact, n3 is No. responses of marginal impact, n4 is No. responses of moderate impact, n5 is No. responses of significant impact, A represents the highest response score, and N is the total number of respondents or total sample size. The analysis applied a research model that incorporates dependent, independent, and moderate variables. The FM roles impact based on the calculated RII which depends on the cohort's opinion over each item, which represents the independent variable while occupation and experience serve as moderators. To check data credibility, analysis conducted Cronbach Reliability Test as shown in Eq. (2). The Cronbach's reliability test enhances the credibility of survey data by assessing the internal consistency of multiple items within a scale, ensuring robust measurement reliability [25]. Cronbach's alpha evaluates reliability by contrasting the extent of shared variance or covariance within the constituent items of an instrument against the total variance [26].

$$\text{Cronbachs alpha}=\alpha =\frac{\text{k}}{\text{k}-1}\left(1-\frac{{\sum \text{V}}_{\text{i}}}{{\text{V}}_{\text{t}}}\right).$$
(2)

Regarding the required sample size, there are several factors to consider when calculating the sample size for a survey, and the specific formula depends on a few key details. First is the desired confidence level, which represents the probability that the survey results accurately reflect the views of the entire population related to the study. Another important parameter is the margin of error. This represents the maximum amount of tolerable deviation between the sample results and the actual population value. Finally, the size of the entire population size the sample is supposed to represent can influence the sample size. To calculate the required sample size for data validity, the study applied Eq. (3) [27].

$$Sample \; Size (n)=\frac{\frac{{z}^{2} p (1-p)}{{e}^{2}}}{1- \frac{{z}^{2} p (1-p)}{N {e}^{2}}},$$
(3)

where (z) is the critical value of the desired level of confidence, (p) is the maximum probability of variation in the distribution, (e) is the margin of error/desired level of precision, and (N) is the population size. The (z) value has been calculated by the following Eq. (4).

$$Critical \; Value \left(z\right)= \frac{x-\mu }{\sigma },$$
(4)

where (x) is the maximum score value, (\(\mu\)) is the arithmetic sample mean, and finally (\(\sigma\)) is the sample standard deviation.

Finally, the study applied Pearson's autocorrelation coefficient with linear regression, and factor analysis of the results to establish relationships between data parameters. The correlation factor assesses the internal consistency and reliability of our survey, through the calculated item-to-total correlations. The study used the following Eq. (5) to calculate the correlation factor.

$$Correlation \; factor \left(r\right)= \frac{\sum_{i=1}^{n}({x}_{i}-\overline{x })({y}_{i}-\overline{y })}{\sqrt{\sum_{i=1}^{n}{({x}_{i}-\overline{x })}^{2}\sum_{i=1}^{n}{({y}_{i}-y)}^{2}}},$$
(5)

where (n) is the number of data in a variable, and (x) and (y) are the data in feature subsets and target variables respectively. The autocorrelations measure how well each question aligns with the overall theme or construct being measured by the survey. High item-to-total correlations indicate that each question contributes meaningfully to the overall score, while low correlations might suggest a need to revise or remove the question for a more cohesive instrument. This analysis helps ensure the survey captures a unified concept and provides a reliable measure for further data analysis [28].

3 Results and discussion

3.1 Sample testing and characteristics

The analysis of collected data reveals a well-distributed sample. By applying Eq. (2) using the collected data, the sample had Cronbach's alpha factor of 0.91 as shown in Table 1. Thus, the data analysis shows excellent reliability based on Cronbach's alpha data reliability test categorization.

Table 1 Sample Cronbach reliability test
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The authors sent 100 forms by e-mail containing the cloud-based survey to be filled through the online form. Analysis showed that the survey data included 59 responses. To determine the validity of the sampling size, the analysis applied Eqs. (3) and (4) to determine the minimum required sample size (n). Using Eq. (4), the analysis determined the critical value of (z = 0.90). Using the calculated (z) and confidence level of 90% and applying Eq. (3) assuming a margin of error not exceeding 10%, the analysis showed that the minimum sample size (n) is 50 participants. therefore, the sample size is acceptable to represent 238,752 engineers in the Kingdom of Saudi Arabia (KSA) [29]. As shown in Fig. 1 and by applying Eq. (5), the R-squared value of 0.4632 indicates that approximately 46.32% of the variance in the data can be explained by the linear relationship between the analyzed variables. This indicates That There's a moderate positive linear relationship between the different item’s variables.

Fig. 1
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Data autocorrelation regression (generated by Excel Data Analysis Add-on Tool)

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3.2 Sample demographic distribution

The sample cohorts included engineers from different jurisdictions, including clients, consultants, and contractors from the construction and maintenance fields. Figure 2 shows sample stakeholders' representation along with the evaluated sentiment by each category. Figure 3 illustrates a breakdown of each stakeholder group's opinion according to data survey responses. Analysis revealed that received responses are composed of 34% clients/owners, 29% consultants, and 37% contractors. The figures show that the sample represents the three main stakeholders proportionally. Adequate stakeholder representation ensures the inclusion of different sentiments and broader views from the population, limiting biased judgments. The figures advocate for more FM involvement in construction projects since the overall sentiment among the population points out that involving the FM has a significant impact throughout the project. However, the three main parties have some different approaches. Consultant and contractor engineers push firmly for FM involvement, while the clients or owners adopt a more conservative approach. The client's reluctance to support earlier integration of FM in projects could be linked to the increasing administrative burden that directly leads to rising initial costs during construction. The added costs and administrative issues could be very evident in the public sector or government construction projects.

Fig. 2
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Population sentiments over the impact of FM involvement in construction projects

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Fig. 3
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Stakeholders responses breakdown regarding the impact of FM integration

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The results shown in Fig. 4 and Table 2 show that different stakeholders (clients, consultants, and contractors) parties have different views on the integration of FM in the different phases of construction projects, which are the planning, design, and construction phases. Regarding the planning phase, the client's moderate RII of 54.8 reflects a more neutral stance. Clients might recognize the potential value of FM input but may not prioritize it heavily at this early stage. Consultants on the other hand strongly recommend FM involvement as indicated by the RII value of 78.4. Consultants likely value the opportunity to collaborate with FMs on aspects like project locations and functions studies. The contractors' relatively high index of 78.4 suggests openness to FM involvement in planning though less support than consultants. Contractors might see the benefits of early collaboration during planning in avoiding future maintenance challenges that could lead to more operational complexities such as remote locations and project logistical print. Results of the design phase show a major difference from the planning phase. Clients increased RII of 74.3 compared to the previous phase reflects a more positive stance from clients. They likely see the value of FM involvement in the design phase, particularly for its potential to contribute to long-term cost savings and improved building performance. Consultants RII 82.1 remains a high value, showing strong consultant support for FM involvement. They likely appreciate FM input on selecting maintainable building systems and designing for efficient operation, which can streamline the construction process and enhance the building's functionality. Contractors RII is the highest index among the stakeholders, indicating very strong support from contractors for FM involvement during design. This implies that contractors recognize the benefits of early collaboration in avoiding future complications and rework related to maintenance considerations. Construction phase results show similar approaches to FM involvement. The client's moderate index of 63.4 reflects a more cautious approach from clients. They might occasionally see value in FM involvement for specific tasks during construction but may not prioritize a continuous role at this stage. Both Contractors and Consultants share the same perspective with RII 76.8. This relatively high index indicates a moderately supportive stance for both groups. They might see the potential benefits of FM involvement in specific areas, such as resolving minor construction discrepancies or reviewing shop and As-built drawings for maintainability. However, extensive involvement during this phase might be met with some resistance due to concerns about potential delays or disruptions to the construction workflow. Contractors may show some resistance due to concerns of additional scrutiny and impact on construction costs while consultants may be less flexible and more rigid regarding design and specifications.

Fig. 4
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FM Relative Importance Index (RII) for each construction phase

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Table 2 Project phases Relative Importance Index
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To summarize the results, the overall support index across the project solidifies the different approaches of the stakeholders. Clients, consultants, and contractors having indexes of 64.2, 80.5, and 79.5 indicate that contractors and consultants share a closely similar view in supporting the FM's important roles in construction projects. Results proved that Clients on the other hand are the most hesitant party to support the FM involvement in the projects. The consultant's group on the other hand expressed the most support for FM integration which can be linked to that additional FM supervision may be beneficial to consultants. Furthermore, the contractor's moderate support can be linked to concerns of additional scrutiny during the execution of works. Therefore, study results implore the need for further research focusing on addressing client’s concerns. The client’s reluctance proved by the study coincided with findings in previous similar studies, which pointed out that client reluctance can be linked with added costs and administrative issues [30]. Clients might worry that FM involvement during construction could lead to delays or disruptions to the workflow. This could be due to concerns about additional review processes that may result in duplication of roles between FM and consultants or potential disagreements between FMs and contractors. Also, clients might not fully understand the benefits of FM involvement during construction. They might perceive FM expertise as more relevant during the planning and design phases, focusing on the building's initial functionality. Overall population results show that the three phases of planning, design, and construction have overall indexes of 71.6, 79.9, and 72.3. The results proved that the design phase is the most crucial phase for FM involvement. This outcome can be seen in previous studies focusing primarily on the design phase [31, 32]. This also fosters the findings related to the mentality of design for maintainability [33,34,35]. Therefore, FM involvement in the design phase is essential regardless of project scope, function, or specifications.

3.3 Primary and secondary roles of FM in construction projects

The FM roles can be categorized into primary and secondary roles. Primary roles are the ones that necessitate FM involvement to maximize future operational efficiency. Secondary roles are recommended to improve the FM practice. Primary and secondary roles are listed in Table 3. The classification is based on the individual relative Importance Index (RII) of each item shown in Fig. 5. The overall RII varied between 60 to 85; therefore, the value 75 which is the overall RII is selected as a datum for classification. Items with an Index over 75 can be described as primary roles, while items with RII less than 75 fit into secondary roles. The results show that the most crucial phase in integrating FMs is the design phase. Most of the items in the design phase fit into primary roles, while the planning and construction roles are primarily secondary.

Table 3 FM’s primary and secondary roles based on RII
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Fig. 5
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Individual RII of Potential FM Roles in the Project

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3.4 Roles during the planning phase

The planning phase is the first phase of the project, and FMs could be involved in multiple fields during this phase. However, FMs have a minimal overall role during this stage. As shown earlier, The RII of the items studied for the planning phase varied from 60 to 80. Determination of Objectives and Function of each Project is performed after the study of the population requirements. The results show that FMs could be heavily involved during the population requirements study since they are primarily responsible for providing operational services. FMs' potential influence in determining project objectives and functions had around 80 in the RII. Scope of Work specifies the boundaries of the work in the construction project. A clear definition of the scope of work is essential to avoid future disagreements between multiple parties. The scope depends mainly on the objectives and the intended project function; therefore, the Facility Management role in the Scope of Work determination is minimal. The data analysis results support this conclusion with only 72 index. The feasibility of any construction project depends not only on the construction costs but also on the long-term operational costs. Therefore, the FM's participation is recommended although not considered essential which had 71 RII. The operational costs include maintenance, repair, security, and contingency costs. Carefully studying all the costs mentioned earlier is essential for evaluating the project's earned value. A study of this scale would undoubtedly factor in the long-term facility operational data. The location of the project largely depends on the project function and users' requirements and characteristics. The project function was addressed earlier. The population requirements provided by the client should be based on FM feedback from other similar projects. For that, the FM has some influence in selecting project location and would be consulted. The results advocate for that with 75 on the RII indicating primary FM role. The human factor is critical in any construction project. Nevertheless, with the least RII 60 and according to the feedback analysis results the FM almost has little to no role in selecting and managing the construction staff since this is the project management staff's responsibility. This is because most of the construction staff leave the project after completion and commissioning. Instead, the maintenance and operation staff handle the operation. However, the FM could be consulted if some construction staff members would transfer to operational staff. Some construction staff members' transfer provides multiple advantages: quick identification of potential defect points and swift response to maintenance and operation malfunctions.

3.5 Roles during the design phase

The design phase is the second phase of the project, and FMs could be involved in multiple fields during this phase. Therefore, FMs have a significant and crucial role during this stage. The analysis provided that the design phase RII is generally higher than the planning and construction phases varying from 69 to 88 mostly above 75, therefore considered primary. The FM and design department must have constant coordination in every step of the design. Involving FMs in every step of the design increases the overall operational efficiency dramatically by reducing maintenance costs. Creating joint coordination committees between the FM and design departments would significantly improve the design quality and long-term efficiency. The membership of the joint committee must cycle between various FM department members to ensure a more comprehensive role. Architectural design has a direct influence on the facility's operational costs. For example, architectural elements affecting maintenance include the cleaning process of high-elevation arches or lighting positioning, which might require particular equipment types. The special equipment could significantly increase the maintenance costs of the facility. Also, some architectural elements require elevated safety precautions, which directly improve risk and cost. The existence of multiple hardpoints would also increase the time and labor required for cleaning works. Therefore, the FM's consultancy in architectural elements is crucial for improving long-term operational efficiency. This is supported by RII of 85. The review of the design drawings includes structural, mechanical, and electrical drawings. The FM's role in reviewing design drawings is minimal. Therefore, the FM's involvement in design drawings is not essential which had a RII of 74. This could be linked to the fact that many of the decisions in this stage are conducted based on design professional codes of practice. However, the FM could still participate in estimating design loads, especially in thermal loads and mechanical systems, which significantly improve the system's overall efficiency. For instance, the design of the Airconditioning ducts has a considerable impact on maintenance capability. The FM's involvement in firefighting system design is crucial to ensure long-term sustainability and improve safety. The FM must participate in the selection of fire suppression system type, determining the level of hazard in the facility, fire system pump criteria, and fire warning device types and locations. This task had the highest RII among all potential roles discussed in this research. The FM has a moderate role in studying the facility's potential user population's behavior and movement with an index of 77. Since the study of future facility users is based on data regarding current facility users. Therefore, FMs could participate in such an endeavor. The FM's involvement in studying the potential users' movement patterns could massively influence the location of main entrances, secondary entrances, emergency entrances, services (for instance: toilets and kitchens), and the insurance of smooth transition inside the facility. The preparation of project requirements and specifications must ensure the durability and sustainability of the project. Therefore, the involvement of a Sustainability Facility Professional is beneficial and considered a primary endeavor supported by an analysis index of 77. This includes the method of execution and materials of every item in the project. FM participation could also be beneficial not merely to public project's sustainability but also to private enterprises. For instance, in hotels and commercial buildings, it is advisable to involve the operating companies earlier in the project to ensure that the project is always compliant with international hotel specifications. It is also strongly advisable to involve FMs in hospitals, Factories, and commercial centers projects. The selection of materials in construction projects should be dependent on multiple factors. These factors directly affect long-term operational efficiency. Therefore, FM involvement is required and could be regarded as a necessity with an RII of 86. The proper FM integration ensures that the selection of the materials is based on the following:

  • The direct procurement cost of the materials for replacement.

  • The availability of the materials on the local market ensures quick replacement and short operational stops.

  • Simple maintenance procedure requires lesser labor expertise which indirectly reduces the operational and maintenance cost.

  • Lower consumption of energy significantly improves environmental protection efforts and sustainability.

The FM might have a marginal role in the quantity and cost estimation of the project with only 69 RII. Thus, the FM does not have to be involved in every step of the quantity and cost estimation since it has no long-term effect on the quality and operational efficiencies. However, it is still beneficial to consult the FM over the overall cost to include in the project feasibility study.

3.6 Roles during the construction phase

The construction phase is the project's third phase, and FMs could be involved in multiple fields during this phase. FMs have an essential and crucial role in the final stages of construction since it is the precursor stage directly before the operation. Yet, out of seven potential roles, five had an RII of 67 while the successor roles had 84 and 87. The selection of contractors in public projects goes through the bidding and tender system. Three committees select the contractor of the project. The three committees are the Biddings Disclosure Committee, the Financial Committee, and the Technical Committee. It is beneficial to include the FM in the Technical Committee membership. Since the FM has an extensive database on the long-term sustainability and operational efficiency of past projects executed by the contractors. While in public projects, the selection of contractors is performed through the biddings and tenders’ systems, in private projects, the choice is solely dependent on the owner. Therefore, it can be easier to invite operating enterprises to select contractors, especially in private hospitals, hotels, and commercial centers projects. However, this may negatively impact some contractors that might have close ties with multiple operating companies, resulting in a potential conflict of interest. Therefore, the owner must be cautious in selecting contractors and operating companies. A change request arises when one project party proposes adding an item or modifying an already existing one. The change request is then studied, and if approved by all parties, it becomes a change order. It would be beneficial for the facility management department to be involved in the process. If changed, some items might result in reduced efficiency during the facility's operation phase. The FM could have a constant and periodic evaluation of all works during construction. This could be achieved by establishing joint committees between the supervising staff and the facility management department. The joint committee would allow the FM to propose change requests and join the studying committee. This allows the project to adapt to the constant technological development affecting project feasibility in the long term. Another positive effect is allowing the facility management staff to detect items that do not comply with operational standards that have not been explored or have been overlooked during the design phase and propose a change request. This allows for an early change order and minimizes the change costs. This is crucial in hotels and hospital projects. The FM's participation in reviewing As-built drawings is paramount in all projects with an RII of 84. The importance of As-built drawings arises in the long-term operational phase. The existence of a reliable drawings archive is essential for efficient facility management. The operation staff would continuously review As-built plans to perform their duties, especially for repair and retrofitting works. The involvement of the FM is crucial in The Handover and Commissioning stage. During this stage, the testing and commissioning of the project are performed. The project enters the operation phase after the handover to the FM. Therefore, the FM is the most crucial member of the handover and commissioning process. This could be noticed by the RII of 87.

3.7 Proposed model to integrate FM in construction projects

The FM could be integrated into all discussed tasks over project development phases, yet it would prove inefficient and complicated. Improper integration would increase the managerial burden, which directly results in rising administrative costs throughout the project. Another issue is that overlapping tasks between multiple parties might lead to contradicting directions or conflicts. Nevertheless, it is possible to create a construction model that effectively includes and integrates the most critical roles of FMs in construction building upon the outcome discussed previously. A general model should focus on FM integration on the Primary roles while the Secondary roles could be included in a more immersive model based on the status of client institution characteristics. Figure 6 exhibits the proposed model to effectively integrate FM in construction projects while preserving managerial flexibility to fit different client institutions and their various administrative systems.

Fig. 6
figure 6

Proposed model to integrate FM in construction projects

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4 Conclusion

At the end of the study, we concluded that FMs have a crucial role during all development phases of construction projects, and it could have a profound impact on the facilities' operation cycle. This impact would vary reducing the operational costs and improving the facilities' resources efficiency and maintainability. Therefore, the outcome of this research provides a comprehensive definition of facility management as an industry and the potential role of FMs in construction project phases (planning, design, and execution). The three primary stakeholder groups have contrasting sentiments involving the integration of FM during construction projects. Clients were the most conservative among the stakeholders while the consultants were the most supportive of the impact of FM integration. The contractors’ individual opinions varied from moderate to strong support. However, the contractor’s overall opinion was moderate while supporting the FM integration with less enthusiasm than the consultants. The impact of FM integration varied during the three phases of the project. FM involvement during the planning phases had the least importance. The FM integration in the design phase of decision-making is essential for a more long-term effective design. This phase is the most important phase to integrate the FM roles. The construction phase had lesser importance than the design phase, yet it’s still imperative to involve FM, especially in the commissioning and pre-commissioning stage at the end of construction. During the planning phase, the FM's roles include determining project objectives and scope of work, studying the project's budget and feasibility, and selecting the project's location. The FM's roles during the design phase include coordination between design and FM departments, architectural design quality and operational efficiency, review of design drawings and loads study, design of firefighting systems, studying users’ behavior and transition in the facility, preparation of tender requirements and specifications, selection of materials characteristics, and quantity and costs estimation. Finally, during the execution phase, the FM's roles include reviewing As-built drawings compliance with the execution works, and handover and commissioning of the facility. The FM roles are categorized into two categories: primary and secondary roles. Primary roles are the ones that necessitate FM involvement to maximize future operational efficiency. Secondary roles are recommended to improve the facility management industry.

Based on the categorization of the primary and secondary roles, a model is proposed to effectively integrate FM into the different phases of construction projects. The model focuses mainly on primary roles while not entirely discarding secondary roles. We recommend the application of the proposed model to ensure a more long-term cost-efficient facility. If involving the FM in all phases of the project proves difficult or unattainable to some institutions for any reason, we advocate for the focus of FM integration primarily in the design phase rather than the whole project. The author pushes for more advanced studies regarding the challenges of integrating FM in projects and discusses methods to overcome them. It’s also recommended for detailed research for the design phase integration specifically. Additionally, the authors push for further specific studies focusing on FM roles in different project types. This may include public projects such as educational, health, administrative buildings, or private commercial projects. Another issue that must be considered is the reasons behind the client’s reluctance to FM involvement. Finally, studying the impact on the reduction of long-term operational costs and improving facility efficiency in a detailed approach might have a tremendous effort to persuade all stakeholders to adopt this endeavor.