Extension card · Plithogenic
Plithogenic AROMAN
This is the form of AROMAN for situations where criterion scores are given as a truth-indeterminacy-falsity triple and criteria carry a degree of contradiction relative to one another. DecisionMind's implementation applies the base AROMAN's two-normalisation and benefit-cost-balance idea in a simplified form; this is explained explicitly below.
Base method
AROMAN →
Philosophy, mechanics, strengths and weaknesses are on the base method card; this card describes only the difference.
Data type (family)
Plithogenic →
What this data type is, when to use it, how to write it in a cell: the family's full account is here.
What Changes from the Base Method?
Four things change; the ranking logic stays the same. A fifth difference, explained separately below, concerns the base method itself.
Cells. In crisp AROMAN every cell is a single number. Here every cell is three numbers: truth (T), indeterminacy (I), falsity (F). The sub-option idea from the plithogenic data-type card is carried, in this family, to the criterion: one criterion is taken as dominant, with a contradiction degree of zero, and how far the other criteria oppose the dominant criterion is given by a contradiction degree between 0 and 1. This degree belongs to the criterion, not to the alternative; it does not vary from alternative to alternative. Criterion weights are an input separate from the contradiction degree.
Early scoring. In base AROMAN, normalisation works on raw numbers. The situation differs in this family: every cell is reduced to a single number at the very first step. First, on a cost criterion, the triple is inverted (T and F swap places); it is then adjusted by the criterion's contradiction degree (truth is enlarged towards the dominant criterion, while indeterminacy and falsity are shrunk by the same proportion); finally, this adjusted triple is reduced to a single number by a score function. AROMAN's two normalisations and its benefit-cost split then operate on this single number.
Scale equalisation. In base AROMAN, every column is equalised separately by both linear (min-max range) and vector normalisation, and the two normalisations are blended with a mixing coefficient. DecisionMind's implementation in this family does this in a chained fashion: every score is first set as a ratio of its own column's largest value, this ratio is then divided by a vector norm to obtain a second scale, and finally the two are averaged. This is not a blend of two INDEPENDENT normalisations as base AROMAN defines it; the second normalisation is built on top of the first, and the mixing ratio in DecisionMind is always 0.5, and cannot be adjusted.
Benefit-cost balance. This is where a substantial departure from the base method occurs. Base AROMAN's distinctive second idea is keeping the benefit and cost criteria's totals separate and combining them with a balance parameter (λ). This family's implementation has no such split: the cost direction is removed entirely at the initial inversion step, and every criterion is then combined into a single weighted sum at the later steps. In other words, DecisionMind's Plithogenic AROMAN does not apply the λ balance that defines base AROMAN; instead, it neutralises criterion direction at the outset and builds a plain weighted sum. This is a structural difference also observed in the same family's neutrosophic member (N-AROMAN); the detail is recorded in the verification notes.
For this family, DecisionMind fixes the early scoring, the chained normalisation blend (fixed at 0.5) and the plain sum without λ. Weights and contradiction degrees are taken from outside, separately.
How to Read the Output
As in crisp AROMAN, the score is a ranking measure meaningful only for this alternative set and these weights; it is not a percentage and cannot be compared with a different analysis.
The difference is here: in base AROMAN, two adjustable parameters (the normalisation blend and λ) lie beneath the score, and the report must show them. In this family, λ does not exist at all; the only adjustable element is the contradiction degrees, and these too must come from the criteria's own structure, that is, from the relationship between criteria rather than from an analyst's preference. Beneath the score there is also T-I-F indeterminacy and the information loss carried by early scoring.
Thus instead of writing:
"According to the Plithogenic AROMAN score, A2 is the best alternative"
the report should read:
"With these weights and these contradiction degrees, A2 has the highest score; this family does not apply base AROMAN's benefit-cost balance (λ), the score is a single weighted sum with criterion direction neutralised from the outset"
When to Prefer This over the Base Method
This extension is used when criterion scores are given as a truth-indeterminacy-falsity triple, and there is a measurable contradiction (opposition to the dominant criterion) between criteria. The contradiction degree must not be a number the analyst assigns "by feel"; it must rest on a basis grounded in the nature of the criteria. Where no measurable basis exists, the warning on the data-type card applies, and the neutrosophic structure is sufficient.
Where hand-adjusting base AROMAN's benefit-cost balance (λ) matters, this extension is not suitable; this split does not exist here. The exit condition is the same as for crisp AROMAN: the matrix must be of a single type, and where no compromise is acceptable on one criterion, this extension too is compensatory.
Mistakes Specific to This Extension
Assuming this extension works with λ. The λ description on the base AROMAN card should not be carried over to this family; there is no benefit-cost split here, criterion direction is neutralised at the outset through inversion.
Assigning the contradiction degree without justification. If a contradiction degree between 0.33 and 0.67 is chosen arbitrarily, the score becomes arbitrary too; the degree must come from a measurable relationship between the criteria (distance, incompatibility).
Skipping early scoring and trying to carry T-I-F through to the final step. This family's engine reduces the triple to a single number at the first step; this is a design decision, not an implementation error, but a different behaviour (such as Plithogenic TOPSIS's late defuzzification) should not be expected here.
Assuming crisp AROMAN's normalisation mixing coefficient is adjustable here. In this family the blend is fixed at 0.5; it must not be presented as a parameter the way it is on crisp AROMAN's card.
The governing principle is this:
The Plithogenic AROMAN score is a single weighted sum, adjusted by the contradiction degree, with criterion direction neutralised from the outset; base AROMAN's benefit-cost balance (λ) is not applied in this family, and the report must state this.
Cases
The first case is DecisionMind's validation example; it is not a page carried over from the literature, and it was verified by running the engine itself. The second case is an illustrative construction.
1. Illustrative example: Plithogenic assessment of three suppliers
Three suppliers are assessed on three criteria: delivery performance and quality-assurance score (higher is better), unit cost index (lower is better). Delivery performance is taken as the dominant criterion, with a contradiction degree of zero; quality assurance's contradiction degree is 0.33, and cost's is 0.67. The weights are 0.40 for delivery performance, 0.35 for quality assurance and 0.25 for cost.
| Supplier | Delivery performance (T,I,F) | Quality assurance (T,I,F) | Cost index (T,I,F) |
|---|---|---|---|
| A1 | (0.70; 0.20; 0.10) | (0.50; 0.30; 0.20) | (0.60; 0.30; 0.20) |
| A2 | (0.80; 0.10; 0.10) | (0.60; 0.20; 0.20) | (0.40; 0.20; 0.30) |
| A3 | (0.60; 0.20; 0.20) | (0.70; 0.20; 0.10) | (0.50; 0.30; 0.20) |
| Direction | higher is better | higher is better | lower is better |
| Weight | 0.40 | 0.35 | 0.25 |
| Contradiction degree | 0.00 | 0.33 | 0.67 |
The method first inverts the cost triple, adjusts every cell by its own criterion's contradiction degree, and reduces it to a single score. It then sets every column as a ratio of its own largest value, divides this ratio by a vector norm, averages the two, multiplies by the weights, and sums.
| Supplier | Score | Rank |
|---|---|---|
| A2 | 0.802 | 1 |
| A3 | 0.697 | 2 |
| A1 | 0.673 | 3 |
The result reads as follows: after direction and contradiction adjustment, A2 has the highest score on delivery performance (0.750) and on the cost index (0.750); A3 is highest only on quality assurance (0.733). Because delivery performance and cost's combined weight (0.65) exceeds quality assurance's weight (0.35), A2 comes out first despite A3's lead on quality assurance. A1 has the highest score on no criterion and therefore finishes last.
Hesitation: if quality assurance's weight is raised from 0.35 to 0.80, and delivery performance is lowered from 0.40 to 0.10 and cost from 0.25 to 0.10 (recomputed independently in Python), A3 moves ahead (0.787) and A2 drops to second (0.763). This is because A3 has a clear lead on quality assurance; once enough weight shifts to this criterion, A3's advantage overtakes A2's advantage on delivery performance.
In the report: "With the given weights, A2 has the highest score (0.802); if quality assurance's weight is raised to 0.80, A3 moves ahead (0.787 against 0.763). In this family the benefit-cost balance is achieved not through a λ parameter but by neutralising criterion direction from the outset; the score is meaningful only for these weights and these contradiction degrees."
Source: DecisionMind's validation example for Plithogenic AROMAN; the figures were obtained by running the engine's own steps independently. The founding-paper attribution recorded in the manifest could not be verified on Crossref (the detail is recorded in the verification notes); for this reason, no author-year is given in the title.
3. What Not to Do
Had the cost index in the illustrative example been mistakenly marked "higher is better," the inversion step would be skipped and a score would be built in favour of the most expensive supplier. The second error is trying to explain this family's score with base AROMAN's λ parameter; there is no λ in this family, criterion direction is neutralised at the outset. The third error is adjusting contradiction degrees by trial and error "to change the result" and presenting this as a sensitivity analysis; the contradiction degree must reflect a measurable relationship between criteria, it is not a tool for producing the desired ranking.
Sources
For the formulas behind each step, the intermediate tables and citation formats, see the DecisionMind method page: decisionmind.app/library/p-aroman
Bošković, S., Švadlenka, L., Jovčić, S., Dobrodolac, M., Simić, V., & Bačanin, N. (2023). An alternative ranking order method accounting for two-step normalization (AROMAN): a case study of the electric vehicle selection problem. IEEE Access, 11, 39496–39507. DOI: 10.1109/ACCESS.2023.3265818
Smarandache, F. (2018). Plithogeny, Plithogenic Set, Logic, Probability, and Statistics. Pons Publishing, Brussels. (no DOI)
Kara, K., Yalçın, G. C., Acar, A. Z., Simic, V., Konya, S., & Pamucar, D. (2024). The MEREC-AROMAN method for determining sustainable competitiveness levels: A case study for Turkey. Socio-Economic Planning Sciences, 91, 101762. DOI: 10.1016/j.seps.2023.101762