Methods · Subjective weighting
HFLPR-PRIORITY (Hesitant Fuzzy Linguistic Preference Relation Priority Programming)
HFLPR-PRIORITY derives a priority order directly from pairwise comparisons decision-makers give in words ("somewhat good," "very good," and the like), without first trying to make those words consistent.
Base method's data type: Hesitant
What Is the Method?
HFLPR-PRIORITY is a method for when you have pairwise comparisons between criteria, and between options, expressed in words ("this criterion is somewhat more important than that one," "this station's vibration problem is markedly worse than that one's," and so on). It derives both the criterion weights and the option priorities under each criterion at the same time. What sets it apart from classical pairwise-comparison methods such as AHP is that, instead of first checking whether the comparisons are consistent and asking the decision-maker to redo them if not, it uses a direct optimisation to find the priority vector that best matches the comparisons as given. Ren, Zhu and Xu proposed it in 2018, together with an application assessing the environmental impact of hydropower stations.
The Philosophy Behind It
The idea behind HFLPR-PRIORITY is to accept that human judgement will always be somewhat inconsistent. Classical AHP computes a consistency ratio; if this ratio exceeds a threshold, it asks the decision-maker to revise the comparisons. In practice this is difficult: an environmental board or a management committee cannot easily "redo" dozens of pairwise judgements it has given. HFLPR-PRIORITY skips this step entirely. Instead, it finds a single priority vector that minimises the worst disagreement across all the comparisons given (every pairwise judgement, including every reasonable term under hesitation).
This idea carries a philosophical consequence. The method does not treat the decision-maker's judgement as "an error to be corrected"; it accepts it as given and produces the single interpretation that best matches that judgement. It also allows judgements to be given as a set of terms (not just a single word, but something like "between somewhat good and very good"), letting the decision-maker carry their own uncertainty forward without collapsing it into a number too early.
How It Works
The method proceeds through seven steps.
First, gathering the pairwise comparisons. Two tables are requested from the decision-maker: a pairwise comparison table among the criteria, and a separate pairwise comparison table among the options for each criterion. Each cell may contain one or more reasonable terms from a shared linguistic term set (for example, a nine-point scale running from "very poor" to "very good").
Second, structural checking. Each table's diagonal must represent indifference, and reciprocal cells (criterion A's comparison against B and B's comparison against A) must complement one another. Tables failing this condition are flagged.
Third, expressing disagreement. For a given table and a candidate priority vector, how much each pairwise comparison agrees or disagrees with that priority vector is computed. If the priority vector matches the table exactly, this disagreement is zero.
Fourth, minimising the worst disagreement. A linear programming model finds the priority vector that minimises the largest disagreement across all the pairwise comparisons (including every reasonable term under hesitation). The constraint is that priority values must sum to one and be non-negative.
Fifth, criterion weights. The fourth step is applied to the pairwise comparison table among the criteria, yielding the criterion weights. These weights are not assigned by the board; they emerge directly from the pairwise judgements between criteria.
Sixth, option priorities under each criterion. The fourth step is applied separately to the pairwise comparison table among the options for each criterion, yielding the option priorities under that criterion.
Seventh, overall priority and ranking. The criterion weights and the per-criterion option priorities are combined by weighting; a single overall priority value is obtained for every option, and the options are ranked from highest to lowest.
The formulas behind each step are given on the DecisionMind method page; this card carries no formulas.
How to Read the Output
The overall priority value shows how far ahead an option stands relative to the others given the pairwise comparisons supplied; it is not a percentage or a probability. Criterion weights are read the same way: if a criterion's weight is high, this criterion has been consistently found more important in the pairwise comparisons between criteria; it was not assigned in advance by the board.
Thus instead of writing:
"HFLPR-PRIORITY found the best option"
the report should read:
"With the pairwise comparisons given, the option with the highest overall priority is this one; the criterion weights, too, are derived from these comparisons and were not assigned in advance"
Data Type and Inputs
HFLPR-PRIORITY works with hesitant fuzzy linguistic data: pairwise comparison cells may contain more than one reasonable term from a linguistic term set. DecisionMind holds no separate data-type extension of this method; it stands alone in its base form.
You need the following: a pairwise comparison table among the criteria; a separate pairwise comparison table among the options for each criterion; and a shared linguistic term set on which all the tables are based (for example, a nine-point scale). The method assumes a single decision-maker; for a group decision, individual tables must first be combined into a single group table. HFLPR-PRIORITY does not require a decision matrix, only pairwise comparison tables; weights are not taken from outside, they are produced directly.
When to Use It, When Not To
HFLPR-PRIORITY is a suitable choice if your data is collected through pairwise comparisons, those comparisons are expressed in words, and it is not practical to ask the decision-maker to redo their judgements because of inconsistency.
The situations in which it should not be used are as follows. If you already have a direct decision matrix (an options-by-criteria table), there is no need to collect pairwise comparisons. If you have more than one decision-maker and want to treat them separately, a group-aggregation step is needed first. If the pairwise comparison tables fail the diagonal and reciprocity condition, the data-collection process should be reviewed first.
Pairwise comparison, expressed in words, inconsistency acceptable → HFLPR-PRIORITY
Pairwise comparison, consistency ratio checked and judgements re-requested if needed → AHP
A direct decision matrix exists → TOPSIS, SAW and similar ranking methods
More than one decision-maker, group aggregation needed → a consensus or aggregation method first
Strengths
HFLPR-PRIORITY's greatest strength is that it produces a priority vector directly, without putting the decision-maker through a consistency check that forces them to redo their judgements; in practice this reduces meeting time and decision-maker fatigue. Producing criterion weights and option priorities within the same framework and the same pairwise-comparison logic removes the need for a separate weighting method. Working with hesitant linguistic data lets the decision-maker remain undecided between more than one reasonable word.
Weaknesses
Its limitations arise from its data structure and its reliance on a single decision-maker. First, the method assumes a single decision-maker; group decisions require individual tables to be combined first, which is a separate source of uncertainty. Second, criterion weights being derived directly from pairwise comparisons between criteria means a criterion's weight can be overly sensitive to a handful of judgements given during comparison. Third, a table that fails the diagonal and reciprocity condition undermines the method's foundation; this condition must be reverified on every use. Fourth, the approach of minimising the worst disagreement targets only the worst case, not the average disagreement; this can let a single extreme judgement affect the entire priority vector.
Common Mistakes
The most common mistake is feeding a pairwise comparison table straight into the method without verifying the diagonal and reciprocity condition; if this condition is not met, the result is unreliable.
A second mistake is running the tables of more than one decision-maker separately, as if there were a single decision-maker, without combining them, and then comparing the results. A third mistake is forgetting that criterion weights come directly from pairwise comparisons and presenting them as though they were "predetermined" by the board. A fourth mistake is failing to look back at which pairwise judgements a criterion's disproportionately high weight stems from.
The governing principle is this:
An HFLPR-PRIORITY result is the best-matching interpretation of the pairwise comparisons given; if one comparison changes, both the criterion weights and the option priorities can change.
Cases
Each case opens with a decision table, describes in words what the method does to it, and shows how to read the result.
1. Environment: Assessing the environmental impact of four hydropower stations (Ren, Zhu and Xu, 2018)
An environmental board will compare the environmental impact of four hydropower stations (Xiangjiaba, Xiluodu, Pubugou, Ertan). Four adverse-impact criteria have been set: vibration, atomisation (water vapour), erosion and ventilation impact. Using a nine-point linguistic scale, the board has given pairwise comparisons both among these four criteria and among the four stations under each criterion; for some comparisons it has proposed more than one reasonable term.
The method first derives the criterion weights from the pairwise comparison table among the criteria. When run on this manifest example, the DecisionMind engine computes weights of 0.151 for vibration, 0.438 for atomisation, 0.173 for erosion and 0.239 for ventilation; these weights were not assigned in advance by the board, but emerged directly from the pairwise judgements between criteria. The priority of the four stations under each criterion is then computed with the same method and combined with the criterion weights.
| Station | Overall priority |
|---|---|
| Xiluodu | 0.2857 |
| Ertan | 0.2771 |
| Xiangjiaba | 0.2429 |
| Pubugou | 0.1943 |
The result reads as follows. Xiluodu has the highest overall priority; this is heavily influenced by its comparative standing on atomisation, the most heavily weighted criterion, against the other stations. Pubugou has the lowest priority and stands out as the station with the most adverse environmental impact profile.
The board hesitates here: the weight given to atomisation (0.438) is close to the sum of the other three criteria. This means the relative importance given to atomisation in the pairwise comparisons between criteria, on its own, largely determines the final ranking. The board should further discuss whether the atomisation comparisons really warrant being this dominant.
In the report: "Xiluodu has the highest overall priority (0.2857); this result stems largely from the 0.438 weight given to the atomisation criterion, and how this weight emerges from the pairwise comparisons between criteria should be shown separately in the report."
Source: The figures are taken from the hydropower station example in Ren, Zhu and Xu's (2018) paper, and the DecisionMind engine reproduces the paper's own ranking (Xiluodu, Ertan, Xiangjiaba, Pubugou) and near-identical priority values on this manifest example.
2. Water Management: An irrigation priority decision between two dam zones
An irrigation authority will decide which of two dam zones should be given priority for its limited water supply. Three criteria have been set: agricultural land area, current water-loss rate, and local residents' drinking-water needs. The authority's management has given linguistic pairwise comparisons both among the criteria and between the two zones; for the water-loss rate, the difference between the two zones has been expressed as hesitant, "between moderate and marked."
The method derives the criterion weights from the comparisons between criteria, the zone priorities from the comparisons between zones for each criterion, and combines them. Suppose the result gives priority to the zone with smaller agricultural land but a lower water-loss rate.
The authority hesitates here: if the water-loss rate criterion's weight comes out markedly higher than the others, whether this weight stems from the pairwise comparisons between criteria or from a pre-existing inclination of the authority should be questioned separately.
In the report: "The zone performing better on water-loss rate stands out in overall priority; since this criterion's weight is higher than the others, the source of that weight (the pairwise comparisons) should be shown clearly in the report."
3. Telecoms: Prioritising base-station investment across three cities
A telecom operator will decide which of three cities should receive priority for its limited investment budget. Three criteria have been set: expected subscriber growth, current infrastructure inadequacy, and competitor density. The planning team has given linguistic pairwise comparisons both among the criteria and among the cities; for some comparisons, more than one reasonable term was recorded because team members disagreed.
The method derives the criterion weights and the city priorities from these comparisons and combines them. Suppose the result gives priority not to the city with the highest expected subscriber growth, but to the one with the most pronounced infrastructure inadequacy.
The team hesitates here: tables satisfying the diagonal and reciprocity condition have been collected, but could a single extreme comparison from one member (for instance, marking a criterion "extremely important") have driven the result on its own? This is a known feature of the worst-disagreement-minimising approach and should be examined further.
In the report: "The city with the most pronounced infrastructure inadequacy stands out in overall priority; how much a single pairwise comparison affected this criterion's weight should be checked separately."
4. What Not to Do
Had it been said, in the hydropower example, that the criterion weights (vibration 0.151, atomisation 0.438, erosion 0.173, ventilation 0.239) were predetermined by the board, this would be wrong; the weights emerged directly from the pairwise comparisons between criteria. A second error is interpreting Pubugou's lowest priority as a categorical claim that "Pubugou's environmental impact is unacceptable"; the priority is only a relative ranking among these four stations. A third error is reporting the result as given without questioning why the atomisation criterion's weight came out so dominant.
Sources
For the formulas behind each step, the intermediate tables and citation formats, see the DecisionMind method page: decisionmind.app/library/hflpr-priority
Ren, P. J., Zhu, B., & Xu, Z. S. (2018). Assessment of the impact of hydropower stations on the environment with a hesitant fuzzy linguistic hyperplane-consistency programming method. IEEE Transactions on Fuzzy Systems, 26(5), 2981–2992. DOI: 10.1109/TFUZZ.2018.2798598
Ren, P. J., & Xu, Z. S. (2021). Decision-Making Analyses with Thermodynamic Parameters and Hesitant Fuzzy Linguistic Preference Relations. Studies in Fuzziness and Soft Computing, Vol. 409. Springer, Cham. DOI: 10.1007/978-3-030-73253-0
Zhu, B., & Xu, Z. S. (2014). Consistency measures for hesitant fuzzy linguistic preference relations. IEEE Transactions on Fuzzy Systems, 22(1), 34–45. DOI: 10.1109/TFUZZ.2013.2245136
Ren, P. J., Hao, Z. N., Wang, X. X., Zeng, X.-J., & Xu, Z. S. (2020). Decision making models based on incomplete hesitant fuzzy linguistic preference relation with application to site selection of hydropower stations. IEEE Transactions on Engineering Management. DOI: 10.1109/TEM.2019.2962180