Abstract
Recently, the TODIM (an acronym in Portuguese for Interactive Multi-criteria Decision Making) method, which can characterize the decision makers’ psychological behaviors under risk, has been introduced to handle multiple attribute group decision making (MAGDM) problems. Moreover, the probabilistic linguistic term sets (PLTSs) are effective tool for depicting uncertainty of the MAGDM problems. In this paper, we extend the TODIM method to the MAGDM with PLTSs. Firstly, the definition, comparative method and distance of PLTSs are simply introduced, and the steps of the classical TODIM method for MAGDM problems are presented. Then, on the basis of the conventional TODIM method, the extended TODIM method is proposed to deal with MAGDM problems in which the attribute values are depicted in the PLTSs, and its significant characteristic is that it can fully consider the decision makers’ bounded rationality which is a real action in decision making. Finally, a numerical example for green supplier selection is proposed to verify the developed approach and its practicality and effectiveness.
Keywords
Introduction
With the increasing complexity of the MADM problems in real world, it may be necessary to take the decision makers (DMs)’ risk attitudes into consideration in the process of MADM [1]. A.Tversky and Kahneman [2] proposed the prospect theory which is a descriptive theory for decision making under risk. This theory incorporates three significant aspects [2]: (1) Reference dependence. The outcomes are manifested by gains and losses according to a reference alternative. (2) Diminishing sensitivity. For gains, the DMs are risk-averse. But for losses, they are risk-preference. (3) Loss aversion. The DMs are much more sensitive to losses than gains. On the basis of the prospect theory, Gomes and Lima [3] first established the TODIM (an acronym in Portuguese for Interactive Multi-Criteria Decision Making), which is effective to solve the MADM problems where the DMs’ psychological behaviors are considered. TODIM is a valuable approach to consider the DMs’ psychological behavior under risk. Gomes and Rangel [4] applied TODIM method for multicriteria rental evaluation of residential properties. Gomes, Rangel and Maranhao [5] used TODIM method for multicriteria analysis of natural gas destination in Brazil. Krohling, Pacheco and Siviero [6] defined an intuitionistic fuzzy TODIM to MADM problems. Lourenzutti and Krohling [7] gave a study of TODIM under intuitionistic fuzzy and random environment. Zhang and Xu [8] developed the hesitant fuzzy TODIM analysis approach based on novel measured functions. Wei, Ren and Rodriguez [9] designed a hesitant fuzzy linguistic TODIM method with a score function. Mishra and Rani [10] studied the biparametric information measures-based TODIM method for interval-valued intuitionistic fuzzy environment. Wei [11] analyzed the TODIM method for Picture Fuzzy MADM. Huang and Wei [12] gave the TODIM method for Pythagorean 2-tuple linguistic MADM. Wang, Wei and Lu [13] defined the TODIM for MAGDM under 2-tuple linguistic neutrosophic environment.
With the increasing complexity of the socioeconomic environment, it looks less possible for a single decision maker (DM) to consider all relevant aspects in MADM problem. As a result, many decision-making processes in the practical world take place in group settings. In many cases, due to inherent complexity, experts can’t express their opinions or preferences by exact numbers, thus resorting to other qualitative preference relations. Herrera and Martinez [14] defined a 2-tuple fuzzy linguistic representation model for computing with words. Rodriguez, Martinez and Herrera [15] proposed the hesitant fuzzy linguistic term sets s (HFLTSs) for decision making. One of the useful theories in dealing with the MADM or MAGDM problems is the theory of probabilistic linguistic term sets (PLTSs) which was proposed by Pang, Wang and Xu [16]. Recently, PLTSs have become a very hot topic in the area of HFLTSs [17–21] and hesitant fuzzy sets (HFSs) [22–25]. For example, Pang, Wang and Xu [16] formed a framework for ranking PLTSs and conducted a comparison method with help of the score or deviation degree of each PLTS. Bai, Zhang, Qian and Wu [26] defined more appropriate comparison method and proposed a more efficient way to handle PLTSs. Gou and Xu [27] redefined some novel operational laws for linguistic terms, HFLEs and PLTSs based on two equivalent transformation functions. Zhai, Xu and Liao [28] defined the probabilistic linguistic vector-term sets (PLVTSs) to extend the application of multi-granular linguistic information. Kobina, Liang and He [29] developed some Probabilistic linguistic power aggregation operators for MAGDM on the basis of classical power aggregation operators [30–32]. Liao, Jiang, Xu, Xu and Herrera [33] designed a linear programming method for MADM with probabilistic linguistic information. Zhang, Xu and Liao [34] gave a consensus algorithm for GDM with probabilistic linguistic preference relations. Cheng, Gu and Xu [35] researched venture capital group decision-making with interaction under probabilistic linguistic environment. Liang, Kobina and Quan [36] proposed the grey relational analysis for probabilistic linguistic MAGDM based on geometric Bonferroni mean [37–43]. Chen, Wang and Wang [44] developed cloud-based ERP system selection based on probabilistic linguistic MULTIMOORA method and Choquet integral operator. Feng, Liu and Wei [45] established probabilistic linguistic QUALIFLEX method with possibility degree comparison. Lin, Chen, Liao and Xu [46] designed the ELECTRE II method to deal with PLTSs for edge computing. Liao, Jiang, Lev and Fujitac [47] studied the novel operations of PLTSs based on the disparity degrees of linguistic terms in designing the probabilistic linguistic ELECTRE III method. Xie, Xu and Ren [48] researched the Influence of Chinese “New Four Inventions” under the incomplete hybrid probabilistic linguistic environment. Wang, Xu and Gou [49] proposed the nested probabilistic-numerical linguistic term sets in two-stage MAGDM.
Liu and Teng [50] developed Probabilistic linguistic TODIM method for selecting products based on online product reviews. Zhang, Xu and Liao [51] studied the water security evaluation based on the TODIM method with PLTSs. However, the employed distance measures for TODIM method in these two papers [50, 51] are more or less irrational. For example, let us consider two PLTSs L1 (p) ={ s0 (0.2) , s1 (0.8) } and L2 (p) ={ s0 (0.6) , s2 (0.4) }. By Equation (7) in Ref. [50] and distance measures in Ref. [51], it holds that d (L1 (p) , L2 (p)) = 0. Obviously, the two PLTSs are not same completely since L1 (p) contains linguistic term s1 but L2 (p) contains linguistic term s2. Furthermore, the probabilities of linguistic terms in L1 (p) and L2 (p) are also not identical. Therefore, the distance measure between L1 (p) and L2 (p) should not be equal to zero. However, based on the distance measures of Definition 10 in Ref. [52], it has d (L1 (p) , L2 (p)) = 0.2000 > 0. This result reflects the difference between L1 (p) and L2 (p), which means that the proposed distance measures of Definition 10 in Ref. [52] overcomes the deficiency in distance measures in these two papers [50, 51].
The aim of this paper is to extend the TODIM method to the MAGDM with the PLTSs based on the distance measures of Definition 10 in Ref. [52] and entropy weight. The main contribution of the paper can be summarized as follows: (1) the TODIM method is extended by PLTSs based on the distance measures of Definition 10 in Ref. [52]; (2) the probabilistic linguistic TODIM (PL-TODIM) method is proposed to solve the MAGDM problems based on the similarity measures and entropy; (3) a case study for green supplier selection is proposed to verify the developed approach; (4) some comparative studies are given with the PL-TOPSIS method and PL-GRA method to verify the rationality of PL-TODIM method.
The remainder of this paper is set out as follows. In the next section, we introduce some basic concepts related to PLTSs and conventional TODIM method for MADM problems. In Section 3 we propose the TODIM method for MAGDM problems under PLTSs with help of Shannon entropy. In Section 4, an illustrative example for green supplier selection is pointed out and some comparative analysis is conducted. In Section 5 we conclude the paper and give some remarks.
Preliminaries
The mathematical form of PLTS [16] is defined as follows.
At the same time, β can express the equivalent information to the linguistic terms l
α
β is derived by the transformation function g-1:
In order to convenient computation, Pang, Wang and Xu [16] normalized the PLTS L (p) as
On the basis of Equations (4) and (5), the order between two PLTSs is defined as: (1) if
In a MAGDM problem, suppose that there are a set of experts E ={ E1, E2, ⋯ , E
q
} with weight vector η = (η1, η2, ⋯ , η
q
), where η
k
∈ [0, 1], k = 1, 2, ⋯ , q,
The TODIM method [3] which was developed to consider the DM’s psychological behavior can effectively solve the MADM problems. Based on the prospect theory, this approach depicts the dominance of each alternative over others by constructing a function of multi-attribute values.
Let A ={ A1, A2, ⋯ , A
m
} be a discrete set of alternatives. Let G ={ G1, G2, ⋯ , G
n
} be the set of attributes, w = (w1, w2, ⋯ , w
n
) be the weight vector of attributes G
j
, where w
j
∈ [0, 1], j = 1, 2, ⋯ , n,
In this section, we shall combine the distance measures and entropy of PLTSs to construct a novel probabilistic linguistic TODIM method for MAGDM problems. We also develop the corresponding methods to derive the weight values for decision makers and attribute.
MAGDM problems description
The following assumptions or notations are used to represent the probabilistic linguistic MAGDM problems. Let A = { A1, A2, ⋯ , A
m
} be a discrete set of alternatives, and G ={ G1, G2, ⋯ , G
n
} with weight vector w = (w1, w2, ⋯ , w
n
), where ω
j
∈ [0, 1], j = 1, 2, ⋯ , n,
Computing the weight values for decision makers
In this section, the weight values for decision makers are determined on the basis of similarity degree. Then the weight values for decision makers can be derived as follows:
(1) Compute the average decision matrix
(2) The degree of similarity between
Furthermore, we can calculate the
(3) Calculate the decision makers’ weight η
k
as follows:
The decision makers’ weight determined by this kind of method has the desirable characteristic: the closer an evaluation value is to the mean value, the larger the weight is. This can avoid the unduly high or low evaluation values induced by decision makers’ limited knowledge or expertise.
(4) Then, the experts’ individual linguistic evaluations can be fused into the collective PTLS
Most of the MAGDM in the real-life decision-making problems utilize only subjective weights determined by the decision-maker. However, when it is hard to derive reliable subjective weights, objective weights looks useful [55]. One of the methods of deriving objective weights is the application of the basic concept of Shannon entropy.
Entropy is a conventional term from information theory which is also famous as the average (expected) amount of information [56] contained in each attribute. The larger the value of entropy in a specific attribute is, the smaller the differences in the ratings of alternatives with respect to this attribute. In turn, this means that this kind of attribute supplies less information and has a smaller weight. It follows that this kind of attribute becomes less important in the MAGDM process.
Let us consider the MAGDM decision matrix
(1) Compute the normalized decision matrix
(2) Compute the vector of Shannon entropy E = (E1, E2, ⋯ , E
n
), where:
(3) Compute the vector of diversification degrees H = (H1, H2, ⋯ , H
n
), where:
The larger the degree H j , the more important the corresponding attribute G j .
(4) Compute the vector of attribute weights w = (w1, w2, ⋯ , w
n
), where
To solve the MAGDM problem with probabilistic linguistic information, we try to present a probabilistic linguistic TODIM approach, which is developed in terms of the prospect theory and can depict the DMs’ behaviors under risk.
(1) Calculate the relative weight of each attribute G
j
as:
(2) Based on the Equation (24), we can derive the dominance degree of A i over each alternative A t with respect to the attribute G j :
In order to indicate the functions ϕ
j
(A
i
, A
t
) clearly, we express it in a dominance degree matrix with respect to the attribute of G
j
as:
(3) Calculate the overall dominance degree of the alternative A
i
over each alternative A
t
by the following equation:
Therefore, by Equation (27), the overall dominance degree matrix can be got as:
(4) Finally, the overall value of each alternative A
i
can be derived by the following formula:
And the order of each alternative can be ranked by the principle, that is, the greater the overall value δ (A i ) (i = 1, 2, ⋯ , m), the better the alternative A i .
In general, probabilistic linguistic TODIM approach for MAGDM includes the following computing steps:
Numerical example
In today’s world, environmental issues have received increasingly attention in various countries and regions. Low-carbon economy and circular economy have become the mainstream of Chinese society for the sustainable development. The consciousness of environmental protection is improving among the public, so the business operators should not only create the economic benefits, but also need to consider the impact of the green image for the enterprise in the market competition. Thus, in this section we present a numerical example for green supplier selection to illustrate the method proposed in this paper. There is a panel with five possible green suppliers A
i
(i = 1, 2, 3, 4, 5) to select. The experts selects four beneficial attribute to evaluate the five possible green suppliers: ①G1 is the environmental improvement quality; ②G2 is the price capability of suppliers; ③G3 is the financial conditions; ④G4 is the environmental competencies. The five possible green suppliers A
i
(i = 1, 2, 3, 4, 5) are to be evaluated by using the linguistic term set
Probabilistic linguistic decision matrix by the first expert group
Probabilistic linguistic decision matrix by the first expert group
Probabilistic linguistic decision matrix by the second expert group
Probabilistic linguistic decision matrix by the third expert group
In the following, we utilize the TODIM approach developed to select the optimal green supplier.
Probabilistic linguistic average decision matrix
By Equation (15), we can have:
Furthermore, we can derive the weight values for experts by Equation (16):η1 = 0.3349, η2 = 0.3462, η3 = 0.3189.
Probabilistic linguistic collective decision matrix
From Equations (19)–(22), we can derive the weight values for attributes:w1 = 0.2515, w2 = 0.2523, w3 = 0.2566, w4 = 0.2396.
Firstly, since w4 = max{ w1, w2, w3, w4 }, then G3 is the reference attribute and the reference weight is w r = 0.2566. Therefore, the relative weights of all the attributes G j (j = 1, 2, 3, 4) are w1r = 0.9800, w2r = 0.9832, w3r = 1.0000 and w4r = 0.9338, respectively.
Here we take an example from the information given by the decision matrix. Let θ = 2.5, then the dominance degree matrices with respect to the attributes G
j
(j = 1, 2, 3, 4) are:
Secondly, the overall dominance degree of the candidate A
i
over each candidate A
t
can be obtained by Equation (27), and the overall dominance degree matrix is:
Then, we derive the overall value δ (A
i
) (i = 1, 2, ⋯ , m) of each alternative A
i
using Equation (29):
Furthermore, in what follows, we compare our proposed method with other existing methods including the probabilistic linguistic TOPSIS method [16], probabilistic linguistic VIKOR method [57] (let η = 0.4) and probabilistic linguistic GRA method [36] (let ρ = 0.5). The comparative results are listed in Table 6.
Order of the green suppliers by using different methods
Order of the green suppliers by using different methods
From the above analysis, it can be seen that these above mentioned methods have the same best green supplier A5 and five methods’ ranking results are same. This verifies the method we proposed is reasonable and effective in this paper.
In this paper, we extend the TODIM method to the MAGDM with PLTSs. Firstly, the definition, comparative method and distance of PLTSs are briefly introduced, and the steps of the conventional TODIM method for MADM problems are presented. Then, on the basis of the classical TODIM method, the extended TODIM method is proposed to deal with MAGDM problems with PLTSs and its significant characteristic is that it can fully consider the decision makers’ bounded rationality which is a real action in MAGDM problems. Finally, a practical example for green supplier selection is given to verify the developed approach and to demonstrate its practicality and effectiveness and some comparative analysis are also given to verify the developed approach. In the future, the application of the proposed models and methods with PLTSs needs to be explored in the other decision making [58–66] and many other uncertain and fuzzy environments [67–77].
Footnotes
Acknowledgment
The work was supported by the National Natural Science Foundation of China under Grant No. 71571128 and the Humanities and Social Sciences Foundation of Ministry of Education of the People’s Republic of China (16XJA630005).
