Extension card · Plithogenic
Plithogenic OCRA
Plithogenic OCRA is the form of OCRA for situations where input and output criteria are given as a truth-indeterminacy-falsity triple and each criterion carries a degree of contradiction relative to a dominant criterion. It measures the shortfall on the input side and the superiority on the output side separately on these triples, and merges them into a single score at the end.
Base method
OCRA →
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. OCRA's idea of treating input and output criteria separately is preserved exactly.
Cells. In crisp OCRA every cell is a single number. Here every cell is three numbers: truth (T), indeterminacy (I), falsity (F); all three lie between 0 and 1. The sub-option idea from the plithogenic data-type card is carried, in this family, onto the criterion itself. One criterion is taken as dominant and its contradiction degree is zero. How strongly the other criteria oppose this dominant criterion is given by a per-criterion contradiction degree between 0 and 1. Criterion weights are an input separate from this degree and are taken from outside as crisp numbers.
Contradiction adjustment. Crisp OCRA has no such step. Here every cell is first adjusted by its own criterion's contradiction degree: truth is pulled upward towards the dominant criterion, while indeterminacy and falsity are shrunk by the same proportion. This adjustment is applied to BOTH input and output criteria, and BEFORE crisp OCRA's own direction-reversal step.
Input and output calculation. OCRA's own structure already keeps input (cost) and output (benefit) criteria separate, which makes the "complement the cost criterion to reverse direction" step, seen in most fuzzy or neutrosophic extensions, unnecessary. The adjusted triples are first reduced to a single number with a score function (following the logic (truth + (1 − 2×indeterminacy − falsity)) / 2). For input criteria, how far each alternative falls behind the best score is calculated; for output criteria, how far ahead of the worst score it lies is calculated; both follow the same steps as crisp OCRA.
Merging. The input and output totals are each zeroed against their own worst value and summed; this is crisp OCRA's third step, and it operates here, unchanged, on the values that have already been reduced to scores.
DecisionMind fixes, in this family, the contradiction adjustment and the score function, followed by crisp OCRA's own input/output split; weights and contradiction degrees are taken from outside and separately from one another.
How to Read the Output
The preference score is read as in crisp OCRA: a relative advantage over the least competitive alternative in this particular set, not an absolute performance percentage. See the OCRA card.
The difference is here: beneath the score lie both T-I-F indeterminacy and an assumption about the contradiction degree between criteria. In the illustrative example below, A2 leads clearly at 0.1871; the gap between A3 (0.0283) and A1 (0.0000) is small, and A1 moves ahead of A3 once C2's contradiction degree is raised from 0.33 to somewhere above roughly 0.45.
Thus instead of writing:
"Plithogenic OCRA gives a more reliable result because it also accounts for contradiction"
the report should read:
"The contradiction degree between criteria has been given under the following assumption; A2 leads by a clear margin, while the ranking of A3 and A1 is sensitive to this assumption"
Taking contradiction into account does not automatically make the result more correct; it merely makes visible which assumption is influencing the score.
When to Prefer This over the Base Method
This extension is preferred where criteria can be split into inputs and outputs and criterion scores are given as a truth-indeterminacy-falsity triple. One further condition applies: some criteria must carry information that is more "independent", or more "in conflict", than others. If the T-I-F triple alone is sufficient and no such dominance-contradiction relationship exists among the criteria, neutrosophic OCRA is already sufficient; the plithogenic form adds one further assumption, and if that assumption is given without justification it creates a spurious distinction.
Converting a measured criterion into a T-I-F triple manufactures indeterminacy rather than modelling it. The exit condition for crisp OCRA applies equally here: if every criterion is an input, or every criterion is an output, none of the method's two-sided structure contributes anything; and if no compromise is acceptable on one criterion, this extension too is compensatory and will not eliminate anything below a threshold.
Mistakes Specific to This Extension
Marking input and output criteria incorrectly. As in crisp OCRA, this error reverses the entire ranking here too; contradiction adjustment does not correct it, and simply carries the wrongly marked direction through unchanged.
Violating the value space. Every cell must be a valid T, I, F triple, and a contradiction degree must be declared for every criterion; running the method with a missing or invented contradiction degree invalidates it.
Assigning the contradiction degree without justification. In the illustrative example, raising C2's contradiction degree from 0.33 to roughly 0.45 reverses the ranking of A1 and A3. If this degree is given "by feel", the ranking becomes a feeling too; the degree must rest on a measurable justification for how independent, or how overlapping, a criterion's information is relative to the dominant criterion.
Changing the defuzzification method. The score function is fixed; comparing against a different score function is a difference of definition, not a difference between methods.
The governing principle is this:
The contradiction degree is a criterion's share of independence or contradiction, drawn from measurable ground; an unjustified figure also makes the ranking produced by OCRA unjustified.
Cases
The first case is DecisionMind's validation example; the figures come from the shared synthetic table of the P-* family, and the engine has been independently run against this same table. The second case is an illustrative fiction.
1. Illustrative example: Three alternatives, three criteria (DecisionMind validation example)
Three alternatives are assessed on three criteria; the first two criteria are inputs ("less is better") and the third is an output ("more is better"). C1 is taken as the dominant criterion, with a contradiction degree of zero; the contradiction degrees of C2 and C3 relative to C1 are 0.33 and 0.67 respectively.
| Alternative | C1 input | C2 input | C3 output |
|---|---|---|---|
| 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) |
| Contradiction degree | 0.00 | 0.33 | 0.67 |
| Weight | 0.40 | 0.35 | 0.25 |
The method adjusts every cell by its own criterion's contradiction degree and reduces it to a single number with the score function. The shortfall behind the best score is calculated for input criteria, and the lead ahead of the worst score for the output criterion; the two sides are then merged at a common zero point. This calculation has been independently reproduced in Python and matches DecisionMind's own validation values (A1=0.0000; A2=0.18708385...; A3=0.02826033...) to a tolerance of 1e-9.
| Alternative | Preference score | Rank |
|---|---|---|
| A2 | 0.1871 | 1 |
| A3 | 0.0283 | 2 |
| A1 | 0.0000 | 3 |
The result reads as follows. A2 has the highest truth on C1 (0.80); because C1 is the dominant criterion, with a contradiction degree of zero, this advantage is not reduced by any adjustment and carries A2 clearly into the lead. The gap between A3 and A1 is small: A3 has the highest truth on C2, but this criterion's contradiction degree (0.33) is moderate; A1 is best on no criterion, but worst on none either, and forms the zero reference point.
The board's hesitation: had C2's contradiction degree been raised from 0.33 to above roughly 0.45, with everything else held constant, calculated independently in Python using the same algorithm, A1 would move ahead of A3. If the weights are shifted from C1 towards C3 (for instance C1=0.20, C3=0.45), A2's first place is not disturbed, only the score gap narrows. This shows that A2's first place is robust, while the ranking of A1 and A3 is sensitive to the contradiction-degree assumption.
In the report: "With the given weights and contradiction degrees (C1=0, C2=0.33, C3=0.67), A2 has the highest preference score (0.1871). The gap between A3 (0.0283) and A1 (0.0000) is small, and their ranking reverses once C2's contradiction degree is raised above 0.45."
Source: This is DecisionMind's validation example for the P-OCRA engine; the input-output triples and contradiction degrees come from the P-* family's shared synthetic table, not from Parkan's (1994) own paper. The plithogenic operations (contradiction adjustment) rest on the formulas defined by Smarandache (2018). The preference scores and sensitivity scenarios were independently recomputed by this card's author in Python.
2. Waste management: A municipality's choice of solid-waste collection contractor
A municipality is to award its solid-waste collection service to one of three contractors. There are two input criteria: unit collection cost and fleet age (both less is better); there is one output criterion: collection coverage rate (more is better). The municipality takes cost as the dominant criterion; it judges fleet age to be partly in conflict with cost, since some low-cost bids rely on ageing fleets, and coverage rate to carry information more independent of cost, and sets the contradiction degrees accordingly. Each contractor is scored on each criterion with a truth-indeterminacy-falsity triple; the indeterminacy comes from incomplete records in the audit reports.
The method adjusts the three contractors by their own contradiction degrees, carries out the input and output calculations, and merges them at the common zero point. Suppose the contractor with the lowest cost also has the oldest fleet, and it still comes first, because the weight on cost exceeds that on fleet age.
The municipality's hesitation: if fleet age's contradiction degree has been kept low, that is, treated as information independent of cost, this contractor's real risk to service continuity may not be visible enough in the score. The municipality should not decide on the preference score alone without applying a separate minimum condition for fleet age.
In the report: "With the high weight given to cost, the lowest-cost contractor ranks first; because fleet age's contradiction degree has been kept low, a separate minimum condition is recommended for service-continuity risk."
3. What Not to Do
If it is forgotten that C3 is an output rather than an input in the illustrative example and it is processed as an input, the output side's reference reverses and the alternative with the weakest output is unjustly pushed ahead. The second error is raising C2 and C3's contradiction degrees arbitrarily "to widen the gap"; the degrees must rest on a justification about the criterion's independence and must not be chosen to pull the ranking in a desired direction. The third error is reducing the T-I-F triples to a single number first, for instance keeping only the T value, and then running crisp OCRA; this erases indeterminacy at the first step and destroys the plithogenic form's only contribution.
Sources
For the formulas behind each step, the intermediate tables and citation formats, see the DecisionMind method page: decisionmind.app/library/p-ocra
Parkan, C. (1994). Operational competitiveness ratings of production units. Managerial and Decision Economics, 15(3), 201–221. DOI: 10.1002/mde.4090150303
Smarandache, F. (2018). Plithogenic Set, an Extension of Crisp, Fuzzy, Intuitionistic Fuzzy, and Neutrosophic Sets – Revisited. Neutrosophic Sets and Systems, 21, 153–166. DOI: 10.5281/zenodo.1408740
Smarandache, F. (2017). Plithogeny, Plithogenic Set, Logic, Probability, and Statistics. Pons Publishing House, Brussels. (no DOI)
Wang, S. (2006). Comments on operational competitiveness rating analysis (OCRA). European Journal of Operational Research, 169(1), 329–331. DOI: 10.1016/j.ejor.2004.07.056
Abdel-Basset, M., & Mohamed, R. (2020). A novel plithogenic TOPSIS-CRITIC model for sustainable supply chain risk management. Journal of Cleaner Production, 247, 119586. DOI: 10.1016/j.jclepro.2019.119586