THE IMPLEMENTATION OF ANALYTICAL HIERARCHY PROCESS (AHP) IN DEVELOPING

Analytical Hierarchy Process (AHP) is one of the most well-known tools in the development of Multi-criteria decision-making framework. AHP is used mainly for concentration on criteria weighting determination and alternative assessment. AHP is able to allow the consistency in participant judgment leading to high quality final decisions. A striking feature of this tool is a pair-wise comparison to assist in determining criteria weightings. A pair-wise comparison is a one-on-one comparison based on how much one criterion dominates another in the context of a project. It forces the selection of one criterion over another. The pair-wise comparison is a basic step for establishing square matrix structure of computing criteria weightings. Based on this, alternatives are assessed for providing the rankings as a reference to finalise a decision. AHP has been implemented commonly in previous studies, such as project procurement method selection, sustainable building certification selection, green building assessment tool, occupant perceptions towards indoor environmental quality performance and setting key performance indicators or priorities (Jin Lin et al. (2014). The research of Jin Lin et al. (2014) employed AHP to establish a multi-criteria decision- making (MCDM) framework regarding the selection of procurement methods for building

maintenance projects. Based on the principles of AHP, this research undertook an identification of criteria associated with procurement methods in maintenance projects. The application of AHP aided in determining two primary components of MCDM framework, including possible assessment criteria and alternatives available for procurement selection. With this tool, judgment consistency was determined for checking participant judgments in their responses. With the assistance of AHP, MCDM framework was expected to be a useful tool for procurement method alternatives and criteria for procurement selection resulting in the most appropriate procurement method recommended. Hence, decision-makers were able to discuss and make final decisions regarding a procurement method in their projects. For selection of sustainable building assessment/certification, Medineckiene et al. (2015) established a new MCDM technique for criteria determination. AHP, which was considered a well-known method of MCDM tools, was used for determining criteria weights. These criteria weights impacted the choice of sustainable assessment/certification. In this research, the scale judgement was based on criteria significance as being less or more important. Following this was a development of new integrated MCDM model for selecting sustainable certification. By applying MCDM model, a building certification was defined by final calculated scores rather than the assessment of building performance in a separate criterion. Ali and Al Nsairat (2009) also developed a MCDM framework supporting the selection of green building rating tools. The MCDM framework development was assisted by AHP in the form of a mathematical decision-making technique for either quantitative or qualitative decision considerations. AHP determined relative importance and weightings for criteria using a square matrix structure. Finally, MCDM framework ranked different alternatives of green building rating tools for offering the best choice in this assessment. The primary role of AHP in this research was the contribution of computing criteria weighting system.

In addition, AHP has been used as the multi-attribute approach in setting key performance indicators (KPIs) and priorities for sustainable intelligent buildings (Alwaer and Clements- Croome, 2010). This research aimed to develop a sustainability assessment model for evaluating the performance of intelligent building systems. AHP was employed to support the determination on relative importance and weights for different sustainability indicators and priorities. Throughout the execution of this multi-attribute approach, project stakeholders are able to indicate and select the most suitable list of indicators and priorities for sustainable intelligent buildings.

3.10. CHAPTER SUMMARY

Deriving from the review of sustainability assessment in Section 2.6 and Sections from 3.2 to 3.8, the additional cost for sustainability requirements and decision-making in such projects, models and frameworks were developed from different aspects of building projects. These aspects might be material selection, building shapes/volumes, green suppliers, lifecycle cost and benefits assessment, the measures of low carbon building, building design methods and building rating systems. However, these models and frameworks primarily focus on assessing sustainability contributions from these aspects of the building. Based on the assessment, the sustainability alternative options are recommended. Therefore, sustainability assessment plays an important role for finalising the sustainability practices and outcomes in these projects.

Based on the review of additional cost in Chapter 2 and the review of models and frameworks in Chapter 3, the issue related to additional cost for sustainability requirements has been considered in different approaches. These approaches can be summarised on Table 3.1.

Table 3.1 Summary of different approaches for considering issues related to additional cost

No The approach for considering issues Studies by 1 To demonstrate additional cost through different case

studies on office projects with actual cost data collected from different countries such as UK, US and Australia.

Kats et al. (2003),

Steven Winter Associates (2004),

Ahn and Pearce (2007). 2 To evaluate additional cost according to participants’

perceptions using research survey.

Houghton et al. (2009)

3 To examine Life cycle cost (LCC) and Life cycle assessment (LCA) models

Or

To suggest the examination of supply chain, such as:  Model of selecting material suppliers

 Assessment model of innovative green features and technologies

Gluch and Baumann (2004), Chen et al. (2011).

Calkins (2008), Akadiri et al. (2013).

Collier et al. (2013), (Sheikh et al., 2011).

Nevertheless, these approaches still contain some limitations in the assessment of sustainability contributions in a green office building, particularly the evaluation associated with qualitative and intangible contributions to the environment and society. Learning from these different critiques of models and frameworks, this research focuses on providing a transparent and holistic MPDM framework for sustainability assessment with a consideration of three sustainability pillars. The MPDM framework should be able to assess the intangible and non-numerical contributions of sustainability on three pillars, especially environmental and societal pillars. Starting from the research gap and heading toward concrete action for addressing the research gap, the proposed framework is established, in particular the selection of green features and technologies for meeting varied sustainability requirements. With the aim of this action, Chapter 4 describes and explains the research approach, research methodology and research methods for achieving the research aim. The research design for showing the outline and structure to respond to every research question is also presented in Chapter 4.