İŞLETME KARAR MODELLERİ - Deneme Sınavı - 2

To get a solid grasp on modeling with linear programming, few other explanations have to be made about the program solution: Each feasible solution determines an objective value for the objective function that is being minimized or maximized. The smallest value for minimization program or the largest value for maximization program is the optimal value of the optimal solution. An optimal solution is a feasible solution that reaches the most favorable value of the objective function.

Operations research is an analytical method for the management of organizations that provides mathematical solutions to decision-making problems. There are definitive steps of this approach that make it analytical: 1. Problem definition 2. System analysis for the problem and data gathering 3. Model construction 4. Model solution and testing 5. The decision of implementing the solution

A linear expression is one where the powers of its variables x and y are equal to one.

This linear program has an objective function that is a maximization. An objective function is the function of a linear programming model that is desired to be maximized or minimized.

A feasible solution to this linear program is a value set of these decision variables which satisfy each of the constraints. The only values that satisfy all of the constraints in this linear program are (x,y) = (2,3).

Linear programming provides solutions under some assumptions. These are proportionality, additivity, divisibility and certainty assumptions. In both the objective function and constraints, the contribution of every decision variable is proportional to its value. As a result, proportionality assumption casts out any variable that has an exponent other than 1.

2x₁+1,5x₂+3x₃ ≤ 20 is one of the constraints for the problem above.

First and foremost, the non-negativity constraints of the model restrict the solution area to the first quadrant, which lies above the x1 axis and to the right of the x2 axis. Also the point (2,2) is inside the feasible region for the given constraints.

In the minimization models, the objective function is alternatively named cost function. The reason for this is the ultimate goal of minimizing something is to reduce loss or “cost”.

The important issues are alternatives, objective and the outcomes of the alternatives for the decision making process. The issues about the past decisions and objective occurrence possibility are not related to a basic decision making process. The answer is B.

Finite alternatives is not an negative issue for decision making. On the contrary, the evaluation and decision process will be easy if there are limited alternatives. But the scarce information, risk attitude, uncertainty and negative physiological factors are the issues that makes the decision process more complicated. The answer is E.

The values of alternatives and events are outcomes. The answer is A.

The determination of all possible future outcomes for each decision alternative is the reason for considering the alternatives comprehensively and selection of the best alternative. Answer is B.

In this last step, according to the outcomes of the events, the most appropriate alternative is selected. It is considered as the decision that gives the best solution according to the determined objective. Then, the decision-making process ends. The answer is B.

In decision making under certainty, the decision maker knows outcomes of events for each decision alternative. In this case, because the decision maker knows everything about the problem, it is easier to make the best decision. The answer is C.

Decision makers have information about the probability of occurrence of each events. The probability value can be known precisely or predicted. These possibilities can be obtained from the personal opinions of the decision-maker, from the statistical records held in the enterprise, from expert opinions, from market research. The answer is E.

In that case,

The mentioned person- represents the decision maker

Weather forecast reports - represents the states for decision making about taking an umbrella or not

Taking an umbrella - represents the chosen best alternative,

Not taking an umbrella - represents the other alternative.

The answer is A.

Decision maker has no information and knowledge about outcomes of the events or probability of occurrence of the events. In cases where there is no level of information or knowledge about the outcomes of events, the decision is given under uncertainty. 

But,

When the decision have information about the probabilities of occurrence of the events, the decision making environment is called “decision making under risk”.

The answer is D.

Decision makers have information about the probability of occurrence of each events. The probability value can be known precisely or predicted. These possibilities can be obtained from the personal opinions of the decision-maker, from the statistical records held in the enterprise, from expert opinions, from market research.

For the mentioned case, if the broker is looking for the probabilities of the states of the alternatives, the environment of the decision making process is risky. 

The answer is E.

Equally Likely (Laplace) method indicates that all events occur equally likely if the probability of occurrence of events is unknown. Therefore, calculation is made considering that the event’s possibility occur equally. The final decision is made according to the objective (maximum or minimum) of the problem.