Group decision making is a situation faced when individuals are brought together in a group to solve problems. According to the idea of synergy

Synergy

Synergy may be defined as two or more things functioning together to produce a result not independently obtainable.The term synergy comes from the Greek word from , , meaning "working together".-Definitions and usages:...

, decisions made collectively tend to be more effective than decisions made by a single individual. However, there are situations in which the decisions made by a collection of individuals are riddled with error, or poor judgment. For example, groups high in cohesion have been noted to have a negative effect on group decision making and hence on group effectiveness. Risky-shift phenomenon, group polarization

Group polarization

In social psychology, group polarization refers to the tendency for groups to make decisions that are more extreme than the initial inclination of its members. These more extreme decisions are towards greater risk if individual's initial tendency is to be risky and towards greater caution if...

, and groupthink

Groupthink

Groupthink is a psychological phenomenon that occurs within groups of people. It is the mode of thinking that happens when the desire for harmony in a decision-making group overrides a realistic appraisal of alternatives. Group members try to minimize conflict and reach a consensus decision without...

 are just three examples of the negative consequences that may result from group decision making. Moreover, when individuals make decisions as part of a group, there is a tendency to exhibit a bias towards discussing shared information (i.e., shared information bias

Shared information bias

Shared information bias is known as the tendency for group members to spend more time and energy discussing information that all members are already familiar with , and less time and energy discussing information that only some members are aware of...

), as opposed to unshared information.

Formal Systems

• Consensus decision-making
  Consensus decision-making
  Consensus decision-making is a group decision making process that seeks the consent, not necessarily the agreement, of participants and the resolution of objections. Consensus is defined by Merriam-Webster as, first, general agreement, and second, group solidarity of belief or sentiment. It has its...
  
   tries to avoid "winners" and "losers". Consensus requires that a majority approve a given course of action, but that the minority agree to go along with the course of action. In other words, if the minority opposes the course of action, consensus requires that the course of action be modified to remove objectionable features.
• Voting-based methods
  Voting
  Voting is a method for a group such as a meeting or an electorate to make a decision or express an opinion—often following discussions, debates, or election campaigns. It is often found in democracies and republics.- Reasons for voting :...
  
  
  • Range voting
    Range voting
    Range voting is a voting system for one-seat elections under which voters score each candidate, the scores are added up, and the candidate with the highest score wins.A form of range voting was apparently used in...
    
     lets each member score one or more of the available options. The option with the highest average is chosen. This method has experimentally been shown to produce the lowest Bayesian regret among common voting methods, even when voters are strategic.
  • Majority
    Majority
    A majority is a subset of a group consisting of more than half of its members. This can be compared to a plurality, which is a subset larger than any other subset; i.e. a plurality is not necessarily a majority as the largest subset may consist of less than half the group's population...
    
     requires support from more than 50% of the members of the group. Thus, the bar for action is lower than with unanimity and a group of “losers” is implicit to this rule.
  • Plurality
    Plurality voting system
    The plurality voting system is a single-winner voting system often used to elect executive officers or to elect members of a legislative assembly which is based on single-member constituencies...
    
    , where the largest block in a group decides, even if it falls short of a majority.
• Delphi method
  Delphi method
  The Delphi method is a structured communication technique, originally developed as a systematic, interactive forecasting method which relies on a panel of experts.In the standard version, the experts answer questionnaires in two or more rounds...
  
   is structured communication technique for groups, originally developed for collaborative forecasting but has also been used for policy making
• Dotmocracy
  Dotmocracy
  Dotmocracy is an established facilitation method for collecting and recognizing levels of agreement on written statements among a large number of people...
  
   is a facilitation method that relies on the use of special forms called Dotmocracy Sheets to allow large groups to collectively brainstorm and recognize agreement on an unlimited number of ideas they have authored.

Decision making in social setting

Decision making in groups is sometimes examined separately as process and outcome. Process refers to the group interactions. Some relevant ideas include coalitions among participants as well as influence and persuasion. The use of politics is often judged negatively, but it is a useful way to approach problems when preferences among actors are in conflict, when dependencies exist that cannot be avoided, when there are no super-ordinate authorities, and when the technical or scientific merit of the options is ambiguous.

In addition to the different processes involved in making decisions, group decision support systems (GDSS) may have different decision rules. A decision rule is the GDSS protocol a group uses to choose among scenario planning

Scenario planning

Scenario planning, also called scenario thinking or scenario analysis, is a strategic planning method that some organizations use to make flexible long-term plans. It is in large part an adaptation and generalization of classic methods used by military intelligence.The original method was that a...

 alternatives.

• Gathering involves all participants acknowledging each other's needs and opinions and tends towards a problem solving approach in which as many needs and opinions as possible can be satisfied. It allows for multiple outcomes and does not require agreement from some for others to act.
• Sub-committee
  Committee
  A committee is a type of small deliberative assembly that is usually intended to remain subordinate to another, larger deliberative assembly—which when organized so that action on committee requires a vote by all its entitled members, is called the "Committee of the Whole"...
  
   involves assigning responsibility for evaluation of a decision to a sub-set of a larger group, which then comes back to the larger group with recommendations for action. Using a sub-committee is more common in larger governance groups, such as a legislature
  Legislature
  A legislature is a kind of deliberative assembly with the power to pass, amend, and repeal laws. The law created by a legislature is called legislation or statutory law. In addition to enacting laws, legislatures usually have exclusive authority to raise or lower taxes and adopt the budget and...
  
  . Sometimes a sub-committee includes those individuals most affected by a decision, although at other times it is useful for the larger group to have a sub-committee that involves more neutral participants.
• Participatory, where each actor would have a say in decisions directly proportionate to the degree that particular decision affects him or her. Those not affected by a decision would have no say and those exclusively affected by a decision would have full say. Likewise, those most affected would have the most say while those least affected would have the least say.

Plurality and dictatorship are less desirable as decision rules because they do not require the involvement of the broader group to determine a choice. Thus, they do not engender commitment to the course of action chosen. An absence of commitment from individuals in the group can be problematic during the implementation phase of a decision.

There are no perfect decision making rules. Depending on how the rules are implemented in practice and the situation, all of these can lead to situations where either no decision is made, or to situations where decisions made are inconsistent with one another over time.

Social decision schemes

Sometimes, groups may have an established and clearly defined standards for making decisions, such as bylaws and statutes. However, it is often the case that the decision making process is less formal, and might even be implicitly accepted. Social decision schemes are the methods used by a group to combine individual responses to come up with a single group decision. There are a number of these schemes, but the following are the most common:

• Delegating decisions: where an individual, subgroup, or external party makes the decision for the group. For instance, in an authority scheme, the leader makes the decision; or in an oligarchy, a coalition will make the decision.
• Averaging decisions: this is when each individual member makes an independent private decision, which are later averaged together to give a nominal group decision.
• Plurality decisions: where members of the group vote on their preferences, either privately or publicly. The decision will then be based on these votes in a majority-rules scheme, in a more substantial two-thirds majority scheme, or in a Borda count method that uses ranking methods.
• Unanimous decisions: this is a consensus scheme, whereby the group discusses the issue until it reaches a unanimous agreement. This decision rule is what dictates the decision making for most juries.
• Random decision: in this type of scheme, the group will leave the choice up to chance. For example, picking a number between 1 and 10, or flipping a coin.

There are strengths and weaknesses to each of these social decision schemes. Delegation saves time and is a good method for less important decisions, but ignored members might react negatively. Averaging responses will cancel out extreme opinions, but the final decision might disappoint many members. Plurality is the most consistent scheme when superior decisions are being made, and it involves the least amount of effort . Voting, however, may lead to members feeling alienated when they lose a close vote, or to internal politics, or to conformity to other opinions . Consensus schemes involve members more deeply, and tend to lead to high levels of commitment. But, it might be difficult for the group to reach such decisions .

Moral dimension of decision making

The ethical principles of decision making vary considerably. Some common choices of principles and the methods which seem to match them include:

• the most powerful person/group decides
  • method: dictatorship
    Dictatorship
    A dictatorship is defined as an autocratic form of government in which the government is ruled by an individual, the dictator. It has three possible meanings:...
    
     or oligarchy
    Oligarchy
    Oligarchy is a form of power structure in which power effectively rests with an elite class distinguished by royalty, wealth, family ties, commercial, and/or military legitimacy...
    
    
• everyone participates in a certain class of meta
  Meta
  Meta- , is a prefix used in English to indicate a concept which is an abstraction from another concept, used to complete or add to the latter....
  
  -decisions
  • method: parliamentary democracy
    Democracy
    Democracy is generally defined as a form of government in which all adult citizens have an equal say in the decisions that affect their lives. Ideally, this includes equal participation in the proposal, development and passage of legislation into law...
    
    
• everyone participates in every decision
  • direct democracy
    Direct democracy
    Direct democracy is a form of government in which people vote on policy initiatives directly, as opposed to a representative democracy in which people vote for representatives who then vote on policy initiatives. Direct democracy is classically termed "pure democracy"...
    
    , consensus decision making

There are many decision making levels having a participation element. A common example is that of institutions making decisions that affect those for whom they provide. In such cases an understanding of what participation

Participation (decision making)

Participation in social science refers to different mechanisms for the public to express opinions - and ideally exert influence - regarding political, economic, management or other social decisions. Participatory decision making can take place along any realm of human social activity, including...

 level is involved becomes crucial to understand the process and power structures dynamics.

Control-Ethics. When organisations/institutions make decisions it is important to find the balance between the parameters of control mechanisms and the ethical principles which ensure 'best' outcome for individuals and communities affected by the decision. Controls may be set by elements such as Legislation, historical precedents, available resources, Standards, policies, procedures and practices. Ethical elements may include equity, fairness, transparency, social justice, choice, least restrictive alternative, empowerment.

Empowerment is a person's way of expressing control.

Decision making in healthcare

In the health care

Health care

Health care is the diagnosis, treatment, and prevention of disease, illness, injury, and other physical and mental impairments in humans. Health care is delivered by practitioners in medicine, chiropractic, dentistry, nursing, pharmacy, allied health, and other care providers...

 field, the steps of making a decision may be remembered with the mnemonic BRAND, which includes

• Benefits of the action
• Risk
  Risk
  Risk is the potential that a chosen action or activity will lead to a loss . The notion implies that a choice having an influence on the outcome exists . Potential losses themselves may also be called "risks"...
  
  s in the action
• Alternatives to the prospective action
• Nothing
  Nothing
  Nothing is no thing, denoting the absence of something. Nothing is a pronoun associated with nothingness, is also an adjective, and an object as a concept in the Frege-Church ontology....
  
  : that is, doing nothing at all
• Decision

Decision making in business and management

In general, business and management systems should be set up to allow decision making at the lowest possible level. In large coporations like SAP, FAA or European Airport authrity it is conventional to use the term CDM (Collabortive decision making}.
Several decision making models or practices for business

Business

A business is an organization engaged in the trade of goods, services, or both to consumers. Businesses are predominant in capitalist economies, where most of them are privately owned and administered to earn profit to increase the wealth of their owners. Businesses may also be not-for-profit...

 include:

• Analytic Hierarchy Process
  Analytic Hierarchy Process
  The Analytic Hierarchy Process is a structured technique for organizing and analyzing complex decisions. Based on mathematics and psychology, it was developed by Thomas L...
  
   - widely used procedure for group decision making
• Buyer decision processes
  Buyer decision processes
  Buyer decision processes are the decision making processes undertaken by consumers in regard to a potential market transaction before, during, and after the purchase of a product or service....
  
   - transaction before, during, and after a purchase
• Complex systems
  Complex systems
  Complex systems present problems in mathematical modelling.The equations from which complex system models are developed generally derive from statistical physics, information theory and non-linear dynamics, and represent organized but unpredictable behaviors of systems of nature that are considered...
  
   - common behavioural and structural features that can be modelled
• Corporate finance
  Corporate finance
  Corporate finance is the area of finance dealing with monetary decisions that business enterprises make and the tools and analysis used to make these decisions. The primary goal of corporate finance is to maximize shareholder value while managing the firm's financial risks...
  
  
  • The investment decision
  • The financing decision
  • The dividend decision
  • Working capital management decisions
  • Cost-benefit analysis
    Cost-benefit analysis
    Cost–benefit analysis , sometimes called benefit–cost analysis , is a systematic process for calculating and comparing benefits and costs of a project for two purposes: to determine if it is a sound investment , to see how it compares with alternate projects...
    
     - process of weighing the total expected costs vs. the total expected benefits
• Control-Ethics, a decision making framework that balances the tensions of accountability and 'best' outcome.
• Decision tree
  Decision tree
  A decision tree is a decision support tool that uses a tree-like graph or model of decisions and their possible consequences, including chance event outcomes, resource costs, and utility. It is one way to display an algorithm. Decision trees are commonly used in operations research, specifically...
  
  s
  • Decision analysis
    Decision analysis
    Decision analysis is the discipline comprising the philosophy, theory, methodology, and professional practice necessary to address important decisions in a formal manner...
    
     - the discipline devoted to prescriptive modeling for decision making under conditions of uncertainty
    Uncertainty
    Uncertainty is a term used in subtly different ways in a number of fields, including physics, philosophy, statistics, economics, finance, insurance, psychology, sociology, engineering, and information science...
    
    .
  • Program Evaluation and Review Technique
    Program Evaluation and Review Technique
    The Program ' Evaluation and Review Technique, commonly abbreviated PERT, is a statistical tool, used in project management, that is designed to analyze and represent the tasks involved in completing a given project...
    
     (PERT)
  • critical path analysis
  • critical chain
    Critical chain
    Critical chain project management is a method of planning and managing projects that puts the main emphasis on the resources required to execute project tasks. It was developed by Eliyahu M. Goldratt. This is in contrast to the more traditional critical path and PERT methods, which emphasize task...
    
     analysis
• Force field analysis
  Force field analysis
  Force field analysis is an influential development in the field of social science. It provides a framework for looking at the factors that influence a situation, originally social situations. It looks at forces that are either driving movement toward a goal or blocking movement toward a goal...
  
   - analyzing forces that either drive or hinder movement toward a goal
• Game theory
  Game theory
  Game theory is a mathematical method for analyzing calculated circumstances, such as in games, where a person’s success is based upon the choices of others...
  
   - the branch of mathematics that models decision strategies for rational agents under conditions of competition, conflict and cooperation.
• Grid Analysis - analysis done by comparing the weighted averages of ranked criteria to options. A way of comparing both objective and subjective data.
• Hope and fear
  Hope and Fear
  "Hope and Fear" is an episode of Star Trek: Voyager, the final episode of the fourth season. The episode has an average rating of 4.3/5 on the official Star Trek website ....
  
   (or colloquially greed and fear) as emotions that motivate business and financial players, and often bear a higher weight that the rational analysis of fundamentals, as discovered by neuroeconomics
  Neuroeconomics
  Neuroeconomics is an interdisciplinary field that seeks to explain human decision making, the ability to process multiple alternatives and to choose an optimal course of action. It studies how economic behavior can shape our understanding of the brain, and how neuroscientific discoveries can...
  
   research
• Linear programming
  Linear programming
  Linear programming is a mathematical method for determining a way to achieve the best outcome in a given mathematical model for some list of requirements represented as linear relationships...
  
   - optimization problems in which the objective function and the constraints are all linear
• Min-max criterion
  Minimax
  Minimax is a decision rule used in decision theory, game theory, statistics and philosophy for minimizing the possible loss for a worst case scenario. Alternatively, it can be thought of as maximizing the minimum gain...
  
  
• Model (economics)
  Model (economics)
  In economics, a model is a theoretical construct that represents economic processes by a set of variables and a set of logical and/or quantitative relationships between them. The economic model is a simplified framework designed to illustrate complex processes, often but not always using...
  
  - theoretical construct of economic processes of variables and their relationships
• Monte Carlo method
  Monte Carlo method
  Monte Carlo methods are a class of computational algorithms that rely on repeated random sampling to compute their results. Monte Carlo methods are often used in computer simulations of physical and mathematical systems...
  
   - class of computational algorithms for simulating systems
• Morphological analysis
  Morphological analysis
  Morphological Analysis or General Morphological Analysis is a method developed by Fritz Zwicky for exploring all the possible solutions to a multi-dimensional, non-quantified problem complex.-Overview:...
  
   - all possible solutions to a multi-dimensional problem complex
• optimization
  Optimization (mathematics)
  In mathematics, computational science, or management science, mathematical optimization refers to the selection of a best element from some set of available alternatives....
  
  
  • constrained optimization
• Paired Comparison Analysis
  Paired comparison analysis
  In paired-comparison analysis, also known as paired-choice analysis, a range of options are compared and the results are tallied to find an overall winner. A range of plausible options is listed. Each option is compared against each of the other options, determining the preferred option in each case...
  
   - paired choice analysis
• Pareto Analysis
  Pareto analysis
  Pareto analysis is a statistical technique in decision making that is used for selection of a limited number of tasks that produce significant overall effect. It uses the Pareto principle – the idea that by doing 20% of work, 80% of the advantage of doing the entire job can be generated...
  
   - selection of a limited of number of tasks that produce significant overall effect
• Robust decision
  Robust decision
  Robust decision is a term dating back to the late 1990s. It is used to identify decisions made with a process that includes formal consideration of uncertainty...
  
   or Robust decision making
  Robust decision making
  Robust decision making is an iterative decision analytic framework that helps identify potential robust strategies, characterize the vulnerabilities of such strategies, and evaluate the tradeoffs among them...
  
   - method that supports selecting the best possible choice when information is incomplete, uncertain
  Uncertain
  Uncertain may refer to:* Uncertain, Texas, a town in the United States* Uncertain, an album of The Cranberries- See also :* Uncertaintyuncertain as to be, not sure of.Not to be sure of something of the happening....
  
  , evolving, and inconsistent
• Satisficing
  Satisficing
  Satisficing, a portmanteau "combining satisfy with suffice", is a decision-making strategy that attempts to meet criteria for adequacy, rather than to identify an optimal solution...
  
   - In decision-making, satisficing explains the tendency to select the first option that meets a given need or select the option that seems to address most needs rather than seeking the “optimal” solution.
• Scenario analysis
  Scenario analysis
  Scenario analysis is a process of analyzing possible future events by considering alternative possible outcomes . Thus, the scenario analysis, which is a main method of projections, does not try to show one exact picture of the future. Instead, it presents consciously several alternative future...
  
   - process of analyzing possible future events
• Six Thinking Hats - symbolic process for parallel thinking
  Parallel thinking
  Parallel thinking is a term coined and implemented by Edward de Bono. Parallel thinking is described as a constructive alternative to "adversarial thinking", debate and in general the approach the GG3 has been known to advocate...
  
  
• Strategic planning
  Strategic planning
  Strategic planning is an organization's process of defining its strategy, or direction, and making decisions on allocating its resources to pursue this strategy. In order to determine the direction of the organization, it is necessary to understand its current position and the possible avenues...
  
   process - applying the objectives, SWOTs, strategies, programs process
• System Dynamics
  System dynamics
  System dynamics is an approach to understanding the behaviour of complex systems over time. It deals with internal feedback loops and time delays that affect the behaviour of the entire system. What makes using system dynamics different from other approaches to studying complex systems is the use...
  
   - methodology to build systemic models in a group setting with a focus on what causes what (causality) and why. Can derive in qualitative models and quantitative simulation models (see also Group Model Building)
• SWOT Analysis
  SWOT analysis
  SWOT analysis is a strategic planning method used to evaluate the Strengths, Weaknesses/Limitations, Opportunities, and Threats involved in a project or in a business venture...
  
   - Evaluation by the decision making individual or organization of Strengths, Weaknesses, Opportunities and Threats with respect to desired end state or objective.
• Trend following
  Trend following
  Trend following is an investment strategy that tries to take advantage of long-term moves that seem to play out in various markets. The strategy aims to work on the market trend mechanism and take benefit from both sides of the market, enjoying the profits from the ups and downs of the stock or...
  
   and other imitation
  Imitation
  Imitation is an advanced behavior whereby an individual observes and replicates another's. The word can be applied in many contexts, ranging from animal training to international politics.-Anthropology and social sciences:...
  
  s of what other business deciders do, or of the current fashions among consultants.
• The use of a Decision making software
  Decision making software
  Decision-making software is a term integrating decision analysis tools to facilitate a person's decision-making process, which results in a choice of a course of action or a variant among several alternatives...
  
   that provides group decision support.

Decision-makers and influencers

In the context of marketing

Marketing

Marketing is the process used to determine what products or services may be of interest to customers, and the strategy to use in sales, communications and business development. It generates the strategy that underlies sales techniques, business communication, and business developments...

, there is much theory, and even more opinion, expressed about how the various 'decision-makers' and 'influencers' (those who can only influence, not decide, the final decision) interact. Large purchasing decisions are frequently taken by groups, rather than individuals, and the official buyer often does not have authority to make the decision.

Decision Support Systems

The idea of using computerised support systems is discussed by James Reason under the heading of intelligent decision support systems in his work on the topic of human error. James Reason notes that events subsequent to The Three Mile accident have not inspired great confidence in the efficacy of some of these methods. In the Davis-Besse accident, for example, both independent safety parameter display systems were out of action before and during the event.

Decision making software is essential for autonomous robots

Robotics

Robotics is the branch of technology that deals with the design, construction, operation, structural disposition, manufacture and application of robots...

 and for different forms of active decision support for industrial operators, designers and managers.

Due to the large number of considerations involved in many decisions, computer-based decision support system

Decision support system

A decision support system is a computer-based information system that supports business or organizational decision-making activities. DSSs serve the management, operations, and planning levels of an organization and help to make decisions, which may be rapidly changing and not easily specified in...

s (DSS) have been developed to assist decision makers in considering the implications of various courses of thinking. They can help reduce the risk

Risk

Risk is the potential that a chosen action or activity will lead to a loss . The notion implies that a choice having an influence on the outcome exists . Potential losses themselves may also be called "risks"...

 of human error

Error

The word error entails different meanings and usages relative to how it is conceptually applied. The concrete meaning of the Latin word "error" is "wandering" or "straying". Unlike an illusion, an error or a mistake can sometimes be dispelled through knowledge...

s. DSSs which try to realize some human/cognitive

Cognition

In science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...

 decision making functions

Function (engineering)

In engineering, a function is interpreted as a specific process, action or task that a system is able to perform .-In engineering design:In the lifecycle of engineering projects, there are usually distinguished subsequently: Requirements and Functional specification documents. The Requirements...

 are called Intelligent Decision Support Systems

Intelligent support systems

Intelligent Decision Support Systems is a term that describes decision support systems that make extensive use of artificial intelligence techniques...

 (IDSS), see for ex. "An Approach to the Intelligent Decision Advisor (IDA) for Emergency Managers, 1999".
On the other hand, an active/intelligent DSS is an important tool for the design of complex engineering systems and the management of large technological and business projects, see also: "Decision engineering, an approach to Business Process Reengineering (BPR) in a strained industrial and business environment".