CHAPTER 2: THEORETICAL BASIC AND RELATED RESEARCH
2.1.5. Choosing by Advantages (CBA) methods
Definition
Choosing by Advantages (CBA) is a collaborative and transparent decision- making system developed by Jim Suhr, which comprises multiple methods. CBA includes methods for virtually all types of decisions, from very simple to very complex [7].
“Choosing By Advantages (CBA) is not an individual tool or technique. CBA is a decision-making system. It is also a decision-making process, not just a step in the process. The CBA system includes definitions, models, and principles, in addition to
tools, techniques, and methods of decision-making. The principles are central. The definitions and models help explain the principles, and the methods apply the principles.
The CBA system includes methods for virtually all types of money and non-money decisions, from the simplest to the most complex. Sound decision making is the foundation of the CBA system.” Jim Suhr.
The principal goal of CBA method is to assist decision-makers in differentiating options and comprehending the significance of those differences. Decisions in CBA are based on the positive differences between options' advantages rather than their advantages and negatives, preventing duplicate counting.
In general, if Factor 1 has a difference between alternatives calling Difference 1 Factor n has a difference between alternatives calling Difference n, the advantages here can be understood that between Difference 1 (at factor 1) and Difference n (at factor n), which is more important.
Sound decision-making, which includes the techniques we currently see applied in our business, is at the heart of the system.
Sound decision making has four cornerstone principles [8]:
- The Pivotal Principle – decision-makers must learn and skillfully use sound methods.
- The Fundamental Rule of Sound Decision-Making – decisions must be based on the importance of advantages.
- The Anchoring Principle – decisions must be anchored to relevant facts.
- The Methods Principle – different types of decisions call for different sound methods of decision-making.
When CBA is properly implemented, it results in collaboratively made, sound decisions that have concise and transparent documentation. This is helpful when sharing the decision with others, the rationale can be clearly understood. It is also helpful when there is new information or a new stakeholder, and the decision needs to be revisited or updated.
The wording used throughout CBA is standard. Although the language isn't inherently
"unfamiliar" to most people, it is utilized succinctly and consistently.
Alternatives: Two or more construction methods, materials, building designs, or construction systems, from which one or a combination of them must be chosen.
Factor: An element, part, or component of a decision. For assessing sustainability, factors should represent economic-, social-, and environmental aspects. It is important to note that CBA considers money (e.g., cost or price) after attributes of alternatives have been evaluated based on factors and criteria.
Criterion: A decision rule, or a guideline. A ‘must’ criterion represents conditions each alternative must satisfy. A ‘want’ criterion represents preferences of one or multiple decision makers.
Attribute: A characteristic, quality, or consequence of one alternative.
Advantage: A benefit, gain, improvement, or betterment. Specifically, an advantage is a beneficial difference between the attributes of two alternatives
Phases of CBA Decision-Making:
Mossman (2013) [9] determined five phases of decision-making in CBA: stage- setting, innovation, decision-making, reconsideration and implementation which decreases waste while increasing efficiency, respect for team members, and project outcomes including profits.
1. Stage-setting
Describe the problem under discussion and the desirable result. List all the variables and information that are known and will be used to make decisions. Make a list of everyone who will be affected by the decision and make sure they are invited to the table for discussion. There should be at least one representative from each impacted party present.
2. Innovation
Create a number of potential decisions (alternatives) to take into consideration. Make sure your list is as comprehensive as possible; this is the list that the team will be working from when conducting the decision-making process. Make sure all participants in the decision-making process are providing you with a complete picture of the potential possibilities. Identify each alternative's characteristics. What unique feature
does each option offer above the others? At this moment, do not stress about the significance of these qualities, but rather consider what distinguishes each potential course of action.
3. Decision-making
This is the part of the decision that many people associate with “CBA” in AEC industry, the stage where a team goes through the stages below and chooses an alternative.
- Summarize the attributes of each alternative.
- List the advantages of each alternative.
- Decide the importance of each advantage.
- Choose the alternative with the greatest total importance of advantages.
4. Reconsideration
Review the basis on which the choice was made. Given all the available information, does the choice seem to be the best one to make? Allow any member who has doubts to voice them before the choice is made. Everyone who will be impacted by the choice should be given the chance to express their thoughts on it and how it might affect the result. Keep in mind that the outcome is what matters most while making a decision.
5. Implementation
Implement the choice made with the result in mind. To find out how the choice functions in practice and how it may be improved going forward, use the PDCA (Plan, Do, Check, Adjust) method of continuous improvement.
The Tabular Method, which is used to select between two or more mutually exclusive alternatives that are not equally expensive, is maybe the most popular CBA technique.
In everyday business, judgments where a team must pick between options that are mutually exclusive include selecting a building material, a general contractor, equipment, a building design, and who to recruit. The CBA Tabular Method enables the transparent documentation of choices that range in complexity from moderate to highly complicated.
steps as shown in figure below [10].
The advantages of CBA method:
Choosing By Advantages is a method that stands out from others when it comes to the picking dilemma, which is described as choosing one and only one alternative (or a combination of alternatives), the best of all.
Consistency, transparency, anchorage to choose context, avoidance of double counting of data, consensus building, documentation, and ease of decision explanation are all characteristics of "excellent" decision-making methods.
According to Arroyo (2015), CBA is superior to other MCDM methods in many regards [11]:
- CBA is superior to Goal Programming methods when it comes to understanding what are the relevant factors that differentiate the alternatives. Goal programming techniques are designed to optimize an unlimited number of options, but when there are just a few (2 to 10) it makes more sense to use CBA and identify how the alternatives differ from one another rather than establishing an objective formula.
- CBA is superior to Value-based methods, when it comes to consistency and collaboration. Research has shown that the most popular MCDM techniques, AHP and WRC, are ineffective at removing non-differentiating factors. AHP uses pairwise comparisons while WRC uses direct comparisons to weigh factors. Since factors are a representation of a broad idea rather than a context-based evaluation, they cannot be consistently weighted. Could you state, for instance, that productivity is more important than safety when picking a construction method? or that productivity comes second to safety? These are the kinds of inquiries that spark interminable, pointless debates that reveal nothing about the genuine options that are
Figure 2.1: CBA Steps
Step 1 Identify Alternatives
Step 2 Define factors
Step 3 Define criteria for each factor
Step 4 Describe attributes of
each alternatives
Step 5 Decide the advantages of each alternative
Step 6 Decide the importance of each advantage
Step 7 Evaluate
cost
available for selection. CBA, in contrast, is based on comprehending the benefits of one alternative. Therefore, CBA helps decision makers to focus on the decision context and avoid unnecessary discussions.
- CBA is more practical than outranking methods, because one can create a ranking of the best alternatives, which is very useful to compare value vs. cost, to prioritize alternatives, and to allocate money to projects. Outranking methods avoid weighting factors as AHP and WRC do, but they do not produce a ranking of the alternatives.
- Finally, CBA, one of the four MCDM techniques now in use, excels in encouraging cooperation and offering decision-makers a clear justification when making a choice between limited options (2-10).