The Delphi method employs a means of anonymously expressing opinions that are based on methodical procedures. Experts are not permitted to talk, have horizontal contact, or have relationships with anybody other than investigators.     Linstone and Turoff (1975) assert that expert perspectives on the questions covered in the questionnaire are gathered through many rounds of questionnaires. The prediction result produces conclusions that are summarized into the consensus views of the experts after numerous consultations, summaries, and revisions. The Delphi method is distinguished by the fact that the participants do not meet face to face and do not conduct face-to-face conversations.

Qualitative decision-making method

      The qualitative decision-making paradigm is used to make decisions dependent on people who make decisions or subject matter experts. This is known as soft technology, where the decision-makers leverage social science ideas gathered from experience, education, and skills and set a structure that fully utilizes these attributes.

                Eldabi et al. (2002) find that it begins with an examination of the critical components of decision-making artifacts, followed by mastery of local collaboration. This strategy is commonly used in complex situations driven by economic or social qualitative elements, has numerous social and psychological variables, and is difficult to explain in precise numbers. This type of "soft technology" method is the most commonly used by businesses in decision-making, and it compensates for the flaws of "hard" methods that are difficult to apply due to human and social aspects. "Hard" and "soft" technologies collaborate and learn to make better decisions.

　　There are numerous approaches for making qualitative decisions. The management decision-making method, expert meeting method, brainstorming method, Delphi method, and other approaches are regularly utilized, with the Delphi technique being the most common. Due to the uncertainty of many variables, the Delphi decision-making paradigm is particularly appropriate, especially under longevity.

 Quantitative decision-making method

　　In this type of decision-making, mathematical instruments are leveraged to devise models that convey different numerous aspects and associations while calculating solutions to solve some decision-making problems. Jaiswal (2012) discovered that the accuracy and speed of everyday decision-making could be improved through quantitative study of decision-making difficulties. Quantitative decision-making methods are another evidence of scientific decision-making approaches.

　　Risk-based decision-making, deterministic decision-making, and nondeterministic decision-making are the most common quantitative decision-making methodologies.

　　　　1. Risk-based decision-making methods

　　　When decision-makers cannot make a favorable judgment on an unlikely circumstance, risk-based decision-making procedures refer to how they can make decisions based on various probabilities by forecasting the occurrence of various situations. There are numerous approaches for making risk-based decisions. The decision tree method is the most widely utilized. Peterman and Anderson (1999) state that a decision tree strategy could illustrate the associations and related probabilities and lead to the best decision-making approach.

                The decision point is one of five elements that make up a decision tree: the others are the plan branch, the natural state point, the probability branch, and the probability branch's end. The decision tree method is widely used in quantitative decision-making analysis and has a number of advantages: first, it can compare the pros and the probability of achieving a plan's goal; fourth, it can calculate the expected benefits and losses of each plan; and fifth, it can be used for multi-level decision-making analysis of a specific problem.

 

　　2. Deterministic decision-making methods

　　　　Problems of deterministic decision-making: there is only one natural state, and decision-makers can use scientific methods to make decisions. Different types of deterministic decision-making methods exist:

　　 Inventory theory, queuing theory, network technology, and other mathematical model methodologies.

·         Differential extreme value method.

·         Break-even analysis method.

　　3. Methods for making nondeterministic decisions

                (Hußmann, 1993) discovers that the probability of various natural states of nondeterministic decision-making is difficult to estimate, modern decision-making theory summarizes a set of practical and feasible methods based on the characteristics of nondeterministic decision-making problems. Problems such as first assuming some criteria, determining the expected value of the plan based on these criteria, and then determining the optimal value, pessimistic, equal probability, decision coefficient, and regret criteria are the most used criteria for nondeterministic decision-making programs.

 

 

References

 

Eldabi, T., Irani, Z., Paul, R. J., & Love, P. E. (2002). Quantitative and qualitative decision‐making methods in simulation modelling. Management Decision.

 

Hußmann, H. (1993). Nondeterministic algebraic specifications. In Nondeterminism in Algebraic Specifications and Algebraic Programs (pp. 17-42). Springer.

 

Jaiswal, N. K. (2012). Military operations research: quantitative decision making (Vol. 5). Springer Science & Business Media.

 

Linstone, H. A., & Turoff, M. (1975). The delphi method. Addison-Wesley Reading, MA.

 

Peterman, R. M., & Anderson, J. L. (1999). Decision analysis: a method for taking uncertainties into account in risk-based decision making. Human and Ecological Risk Assessment: An International Journal, 5(2), 231-244.