Structural degradation assessment of RC buildings: application of the method of assessment by integrity and safety—MAIS Method—in a heritage case study in Brasilia

The assessment of an existing structure is a complex activity that requires a realistic overview of the materials involved, the acting loads, environmental aggressiveness, and other factors to describe the correct functionality and adequately predict the level of structural safety. This paper proposes a probabilistic methodology that couples reliability analysis to a structural inspection and evaluation process: the Method of Assessment by Integrity and Safety—MAIS Method. The MAIS Method is an innovative approach used to quantify the integrity of existing buildings in reinforced concrete by identifying pathologies that may compromise their structural safety. This method is distinguished by its ease of applicability, which considers uncertainties in the data and, with parameterized inputs, facilitates the collection of variables required for the analysis. The approach streamlines the assessment process, integrating the two fundamental aspects of evaluating a structure: the identification of degradation phenomena and the assessment of the structure's resistance. The method employs probability theory to offer more accurate results, making it more reliable. The MAIS Method was applied to a building in the Asa Sul neighborhood of Brasilia, and with the aid of a risk matrix, was modeled to visualize the reliability of each element of the building. As a result, the structure presented a “medium–high” risk. Therefore, the MAIS Method presented a very satisfactory and consistent result with reality, effectively providing a kick-start to what can be a great contribution to the structural evaluation of assets and properties, and it has enormous potential for application and collaboration in the field of structural assessment.


Introduction
Throughout history, humans have had a deep-seated desire to create lasting things despite nature's cycles and impermanence.This intrinsic characteristic has persisted over millennia, and it is still present today.This is also evident in the field of civil construction, where the market for restoration, conservation, and evaluation of existing structures is rapidly growing.This growth is driven by three main factors: the increasingly urgent and relevant topic of sustainability; the need for buildings to adapt to changing uses and circumstances over time; and society's increasing desire to amplify regional and local expressions of identity.This last factor is a result of the effects of modernity, accelerated lifestyles, and globalization.
As society grapples with these changes, it is as if it is asking itself "who am I?" in the middle of so many changes.Looking at a heritage that represents its identity can help provide an answer.It reinforces society's sense of identity 83 Page 2 of 15 and imbues heritage with greater significance [3].Heritage conservation serves not to preserve the past for its own sake but rather to provide a reference point for cultures to recognize, identify, and build their future upon their values and trajectory while maintaining their social character.
Effective preservation of cultural heritage structures requires careful consideration of conservation methods, such as crack repair or other damage mitigation techniques.However, such efforts are often not considered conservation unless they are essential for maintenance [11].To address this issue, several countries have established legal frameworks and regulations to promote the preservation of historical buildings and international committees, such as the International Council of Monuments and Sites (ICOMOS), International Center for the Study of Preservation and Restoration of Cultural Assets (ICCROM), and the Institute of National Historic and Artistic Heritage (IPHAN) [7] in Brazil have been established to ensure the protection of cultural heritage structures [15].Such an attempt to normalize the subject confirms the expansion and consolidation of the theme.
Numerous methodologies have been developed by researchers to analyze potential damage to cultural heritage and regular structures.These methodologies allow for quantification of damages to facilitate preservation and maintenance of historical and cultural buildings.
The purpose of this article is to introduce and explain the MAIS Method [9], a methodology developed for the assessment and preservation of reinforced concrete buildings based on sensory inspection and apply it to a building located in Brasilia (Brazil).The method focuses on modern heritage structures, but it can also be applied in conventional structures and in condominiums.It employs a probabilistic evaluation approach to determine the building's degree of integrity and safety [10].
The MAIS Method is unique and distinguishes in its formulation for including uncertainties, featuring a parameterized data collection process that optimizes inspection speed, and employing a novel integrity model that is linked to safety using reliability indexes proposed in an international standard.These features enable the method to produce more reliable and accurate results.

Reliability
Professionals in the field of building design and construction cannot guarantee absolute safety due to the high degree of uncertainties in the variables involved in structural projects.Uncertainties arise from the inability to accurately predict future loads and to determine the mechanical or geometric properties of the materials.Simplifying hypotheses are used to predict the behavior of structures under active actions, environmental conditions, numerical limitations, and human factors.
As building designs have become more complex, probabilistic safety verification methodologies have been developed to address the uncertainties inherent in these projects.The reliability index considers the uncertainties associated with physical phenomena, statistical uncertainties due to a lack of data, and gaps in the chosen model.Many uncertainties are qualitative, difficult to quantify and predict, such as material deterioration, performance parameters, environmental impacts, and human factors.These uncertainties make it challenging to define all potential risks in a structural or maintenance project, and time further complicates the issue as it is impossible to determine with certainty the load the structure will support or the material resistance over time.
Reliability analysis is one method used to determine the degree of preservation of a building structure.The data available may or may not accurately reflect reality, and as a result, there is always a probability of failure.The primary objective of reliability analysis methods is to obtain the probability of failure of a system.Reliability is defined as the ability of a structure to perform its designed function during its useful life and measure its chances of violating a limit state due to failure or an unexpected performance.
Reliability-based methodologies require every random variable involved in the problem to be represented by a corresponding probability distribution, which relates a specific value of the variable to its probability of occurrence.This mathematical model is essential in assessing the reliability of building structures.Numerically, Eq. 1 represents reliability.
where R : Reliability.P f : Probability of failure.

Risk management
According to ABNT NBR ISO 31000 [1], risk is the effect of uncertainty on objectives, that is, there are possible events that may or may not occur (uncertainties) and that, if they occur, may prevent, or delay the final goal.The effect is a deviation from the expected result, whether positive or negative, and the objective can have the most varied aspects, such as financial, health or safety goals.
An instrument of great assistance in risk management is the risk matrix, which can also have other names such as probability and impact matrix or risk appetite matrix.It is a management tool that allows you to visually identify which are the risks that should receive the most attention.
It consists of a two-dimensional table, in which the central cells must be associated with a certain color depending (1) R = 1 − P f , on the risk it presents, making it an easy to interpret graph.These two dimensions represent the probability of an event happening and its impact on the project if that event happens.This impact is often related to the cost of repairing this risk.Simply put, it is said that: The risk matrix is widely regarded as an effective tool for visually representing the risks associated with an analyzed object.The risk matrix was chosen as a valuable device, and it was incorporated to the MAIS Method.

Methodologies for the evaluation of reinforced concrete structures
Designing a new structure and evaluating an existing one imply the use of different methodologies.While the former, relying on diverse limit states, can be regarded as a decision-making process, the latter must consider the inherent uncertainties, encompass a greater number of variables, and strive to ensure an appropriate level of safety concerning the prevailing and potential loads [4].Considerable work has been carried out regarding degradation analysis and condition assessment of buildings, which offers significant benefits and relevance to the current societal context and helps to plan maintenance and management on existing buildings.The available methodologies for structural evaluation exhibit significant global similarities and adhere to consistent principles.Generally, each pathological manifestation is linked to the corresponding component using a predefined scale, determined through on-site visual inspections by specific criteria.The severity level of each element is documented in a checklist, which is then incorporated into a formula that provides a numerical representation of the component's condition.Basically, a systematic decomposition of the problem into its basic components for data collection is performed.In essence, the analysis of building degradation is centered around diagnosing each individual pathology within the building elements.
After years of scientific advancement, some methodologies already accepted by professionals in the field are known and have already been applied.One of them is the Condition Rating methodology, released by the Comité Européen du Béton (1998) proposed to be applied in large evaluation populations in which, through a damage index and a deterioration factor, it identifies the elements that are most damaged.In short, it consists of three steps: first, a visual inspection is carried out along with a preliminary assessment of the condition of the structure, observing the applied forces, the structural actions, the hierarchy of importance of its components and the most damaged regions are identified; then the (2) Risk = probability × consequence.
intensity of the pathological manifestation and its extension are verified to determine the numerical index of the level of damage; finally, the safety assessment is carried out with the calculation of the residual strength of the elements.
Recently proposed by a collaboration of Italian, Portuguese, and Brazilian researchers, another methodology known as Alert-D [12] has emerged.Its distinguishing feature lies in the integration of artificial intelligence tools and technological information within a Decision Support System (DSS).Initially, an Analytic Hierarchy Process (AHP) is conducted for construction elements.This process involves the application of four factors to each identified damage: severity of the pathological manifestation, extent of the pathological manifestation, damaged component, and component position.Since each weight is associated with a specific criterion and alternative, and the range of alternatives is known, the weights are automatically assigned.Subsequently, this Hierarchical Analytical Process is applied to a novel formulation of Key Performance Indicators (KPIs), aiming to highlight the occurrence of multiple pathological manifestations within a single component.Finally, the obtained result is utilized in Tuutti's Corrosion Damage Model [14] to determine the degree of structural deterioration.
Another notable approach is the Degree of Deterioration of the Element ( G de ) Methodology, initially developed by Castro [2].It aims to establish criteria for quantifying the level of degradation of individual elements as well as the overall structure.This methodology enables the creation of a periodic maintenance program by prioritizing actions based on the criticality level of each element and, just like the last-mentioned methodology, is based on Tuutti's damage model [14], as discussed in Sect. 4.Over time, the methodology has evolved and undergone refinements, particularly by Fonseca in 2007.The methodology involves dividing the entire structure into elements that are further grouped into families.During on-site inspections, each identified pathological manifestation is assigned a Damage Factor ( F d ) and an Intensity Factor ( F i ).Consequently, the degree of deterio- ration of the element (Gde) is calculated using Eq. 3.
where D i : Damage present in the element.D m áx.: Greater damage present in the element.G de : Degree of Deterioration of the Element.m : Number of pathological manifestations present in the element.
The present methodology is a probabilistic procedure that couples a reliability analysis to the evaluation of the degree of degradation of the structure.For the first time probability is added to the methodology that aims to couple an analysis of its reliability.The safety level of the structure is then coupled through the Reliability Index ( ) .Raising the hypothesis that the variation of the reliability index of the elements, families and structure follow the same law of behavior as the integrity factor.It is allowed, in a simplified way, the coupling of the safety level of the structure.Thus, it becomes possible to find the probability of failure P f .

Method of assessment by integrity and safety-MAIS method
The process of evaluating a building is quite different from that of designing new structures.When designing a building from scratch, the flow of acting forces follows the choice of the structural system and the materials used.Evaluating an already built structure presents more variables and uncertainties, since the behavior of the structure during its time of use depends on several factors, such as natural wear, weather conditions and the way users treated the building, and most of these factors cannot be controlled or quantified.
The MAIS method-Method of Assessment by Integrity and Safety-demonstrated in the work by Oliveira [9], is a novel approach used to quantify the integrity of buildings by identifying pathologies that may compromise their structural safety and integrity.This method is distinguished by its ease of applicability, which considers uncertainties of the data and, with parameterized inputs, facilitates the collection of variables required for the analysis.The approach streamlines the assessment process, integrating the two fundamental aspects of evaluating a structure: the identification of degradation phenomena and the assessment of the structure's resistance.The method employs probability theory to offer more accurate results, making it more reliable.The use of assays may be necessary to fine-tune the MAIS Method, however, such refinements are not essential.Overall, the MAIS Method represents a valuable tool for assessing and quantifying the safety and integrity of buildings in a systematic, rigorous, and scientifically sound manner.
The MAIS Method can be applied in two ways: MAIS Mode 1 and MAIS Mode 2.
MAIS Mode 1 is through the collection of data via on-site inspection, in which performance matrices are assembled and, through simple mathematical formulations, programmable in a small computer system, the integrity factor of each element, class and of the global structure is determined.Additionally, the risk of the structure is evaluated, considering uncertainties by coupling the reliability index.
Mode 2 is via modeling the structure in a specialized software.There is also the phase of data collection via onsite sensory inspection, but in this case the collected data in the inspection is applied only to the elements.Then, when entering the data into the software, before generating the structure, the modulus of elasticity (E) and inertia (I) are changed so that they reflect the raised deterioration of that element, changing the stresses, displacements, and rotations of the structure, that is, changing its response.That input is depreciated so that the result is more assertive.
On this paper only MAIS Mode 1 will be covered.The first step is to find the Integrity of the building, as shown on next topic.

Integrity
The MAIS Method is described in the flowchart in Fig. 1.
The first stage of the methodology is to conduct an anamnesis of the building to obtain as much information as possible, such as age, history, projects, construction techniques, typology, materials used etc.Data classification involves grouping structures into distinct classes, with each class further divided into individual elements.These classes shall be curtains, pillars, beams, ramps/stairs, architectural elements, foundation, expansion joints, slabs, and reservoirs.Classes shall be defined by a qualified professional and each element must be individually named.
The next step of the inspection process is conducted in loco, following the methodology instruction booklet, with all the guidance and tables to be completed according to the elements and damages found.A photographic memory of each analyzed members must be made.Then, for each element, three factors must be applied: • Damage Factor ( F d ): level of relevance of the damage to the functionality of the element.This factor's value is previously defined.• Intensity Factor ( F i ): degree of severity and evolution of damage.This factor is tied to the moment when the inspection takes place and depends about the environment in which the damage is located.The inspector must consider the context.• Extension Factor ( F e ): degree of spread of damage in the element.
Finding the most suitable integrity model posed a significant challenge in this research.This is because the chosen model serves as the foundation for developing the programming formulations.As explained in Oliveira [9], two integrity models and two scales were tested: one based on Tuutti's  [14] research and another one based on Heidecke's work, as presented in Lucio [8].
Tuutti's model is based on the phenomenon of reinforcement corrosion and is comprised of two distinct phases.The first phase, initiation, involves the gradual penetration of deleterious substances into the concrete microstructure until a critical threshold is reached, at which point damage begins.During this phase, anomalies may not be visibly detectable.The second phase is propagation, during which the rate of degradation increases.At this point, pathologies become visible and can be detected through on-site sensory inspections.Heidecke's model is based on his curve, commonly used in depreciation models for engineering evaluations and expertise.
Both models employ variables that represent the Intensity Factor and the Ponderation Factor associated with each pathology, which ultimately contribute to the determination of the Integrity Factor for the analyzed object.Extensive testing was conducted on both equations, leading to the successful generation of a 3D model (as depicted in Fig. 2).
Both integrity models and it is observed that both models exhibit similar behaviors.
Following multiple calibrations, it was determined that Heidecke's model was a superior fit due to its cubic nature, single line composition, and single equation, which increases its reliability and ease of programming.With these features established, the Damage ( D ) formulation derived from the Heidecke's model are expressed by Eq. ( 4).
where D : Damage.F d : Damage Factor.F e : Extension Factor.F i : Intensity Factor.
The calibration of the Damage, Integrity and Extension Factors were made after many attempts and tests.Conclusions are that the most appropriate values are also based on Heidecke's models and correspond to those shown in Table 1.The spread of the Extension Factor was based on the Dutch International Standard for condition assessment of buildings [13].
Knowing the damage of each pathology allows the determination of the overall damage of the element, the Element Damage ( D e ) is found as shown in Eq. 5.In this formula, the first component refers to the greatest existing damage multiplied by a weighted average that represents the other existing anomalies.The second part of the formula (m∕(2m − 1)) compares the first component's value to the maximum attainable damage value of the existing anomalies, that is, as if the value of all the applied factors were equal to 1. Based on the premise that integrity is the complement of damage, Eq. 6 can be derived.
where D e : Element damage.D i : Damage present in the ele- ment.D max ∶ Greater damage present in the element.m : Number of pathological manifestations present in the element.Int e : Element integrity index.
Obtaining the Element Health Index now allows the calculation of the Class Integrity Index (Int c ) .Such informati on is relevant because it quantifies the state of each family of elements thereby aiding in prioritizing the treatment of elements based on their criticality.First, one must follow Eq. 7, proposed by Fonseca [6] to find the Class Damage (D c ) in which to the highest existing Element Damage is added a weighted average of the other damages of the element of ( 4) )  that same class.Following the same reasoning adopted in the previous topics, the Class Integrity Index is presented In Eq. 8.
( The Relevance Factor ( F r ) of each class is assigned on this step.This information establishes the importance of the group and its influence on the global structural behavior performance.The sum of the Relevance Factors must be equal to 1 and its definition is not fixed, it shall be defined by the professional.Table 2

is a guidance table that suggests values for each class.
Ultimately all the data is obtained to find the structure integrity (Int) , which estimates its percentage that is in good condition by analyzing it globally.It is the sum of the Integrity Index of each Class (Int c ) weighted by its respective F r , according to Eq. 9.
where Int : Global structure integrity index.Int c : Class integ- rity index.F r : Relevance Factor.
This value of the global integrity can be classified from critical to high as shown in Table 3. Henceforth, reliability is inserted into the methodology.

Reliability
The use of the reliability index is done simply considering the premise that the variation of Reliability Index ( ) of the elements, classes and structure follows the same law of behavior of the Factor of Integrity.The reliability index is found by directly multiplying the reliability level ( ) with the Global structure integrity index (Int) via Eq.10.
where : Reliability Index of the elements Int : Global struc- ture integrity index.Table 4 and therefore range from 0.8 to 4.3.In the present work this value is set at = 4 because it is considered the most appropriate index for case studies.This means that you directly multiply the reliability level to the Global structure integrity index (Int) shown in Eq. 7 to find the reliability index ( ).

Risk ratings
The risk matrix is a valuable tool incorporated into the MAIS Method.Based on the reference reliability indexes (Table 4), the MAIS Risk Matrix was created (Table 5), allowing the reliability ( ) of the element, class or structure to identify its probability of failure and its consequences.Table 6 presents the classification of this risk according to the Reliability Index found and the actions to be take.

Case study
This work's Case Study pertains to the structural evaluation of two stores situated in CLS 105, South Wing, Brasilia (BR).The choice lies in its location within a region that the United Nations Educational, Scientific and Cultural Organization (UNESCO) recognized as a world cultural heritage site by 1987, owing to its pivotal role in the history of urban planning.Thus, any intervention must be made respecting the typology and architecture of the city and the neighborhood.The building is in an urban area that witnesses substantial human and vehicular traffic, and the terrain is characterized by low slopes and scant vegetation cover, as depicted in Fig. 3.
The commercial property is a reinforced concrete building comprised of two shops, each with two floors, juxtaposed, separated by an expansion joint.It is composed of the ground floor that gives access to the building by the northeast, southeast and southwest facades, by the first floor and by the roof.Figure 3a presents an overview of the heritage.Figure 3b presents, respectively, the aerial view and the northeast facade.
To name and standardize the analysis, the store was divided into: Buildings i and ii; Level 1 (Ground Floor); Level 100 (First floor) and Level 200 (coverage floor).Figure 4 shows the modeling of the structure presenting the basement, which is under the store ii, the ground floor, the first floor and the roof.The basement will not be approached due to the difficulty of inspecting it.
In December 2020, specialized sensory surveys were conducted during on-site visits to collect data on damage, intensity, and extension factors to assess the integrity and reliability of the building, of the classes and of the elements.The classes were divided into pillars, beams, and slabs.

Results presentation
The results will be presented by class.

Pillars
The column class was divided into 18 elements.The central pillars were divided by an expansion joint and were evaluated as one.The technical staff assigned a quantitative value to the existing anomalies on each pillar.The sensory inspection indicates a low to medium degradation of the pillars that presented pathological manifestations such as carbonation, poor covering, corrosion of reinforcements, disaggregation, deplating, concreting failure, cracks, stains, crushing signs and moisture at the base.Figure 5 shows some of the existing pathologies.To access the assigned weight for the Damage, Intensity and Extension factors to each pathology of each element, not only of pillars but also of all classes, check Oliveira [9].

Beams
The beam class was divided into 37 elements.Figure 6 shows some of these pathological manifestations inspected.During the inspection, the pathological manifestations of carbonation, poor covering, reinforcements corrosion, disaggregation, deplating, concreting failure, cracks, stains, signs of crushing and moisture were observed.

Slabs
Six elements compose the slab class: three belonging to Store i and three belonging to Store ii, at levels 100 and 200.During the on-site inspection, the slabs on level 100 of Building were severely degraded, while the others were in good condition.Figure 7 shows some of the pathologies found.

Results analysis
After performing individual and on-site evaluations of each element, the resulting data was organized into Table 7.This table displays the inspection results, the integrity, and the risk level by element.
The overall structure was divided into thirteen classes: four for pillars, five for beams, and four for slabs.These classes were further divided by level and by building.Table 8 presents the results obtained for each class after the MAIS Method was applied.
Table 9 provides a summary view of all the data presented in Table 7 and in Table 8.This table indicates the number of elements and classes that obtained that particular risk level, which ranges from "extremely low" to "extremely high".For  ease of interpretation, the results from Table 9 are graphically presented in the chart of Fig. 8 for the elements and Fig. 9 for the classes.The tables illustrate that the risk level of pillars varies between medium to medium-high, with medium being the most common and accounting for 61.1% of the elements.Although one element, P101, presented critical integrity, its risk level remains within the average range of the other elements in this class.These findings suggest that, despite visible deterioration, the risk level of the pillar is not significantly higher than that of the other elements.It is noteworthy that the medium and medium-high risk classification is the most prevalent in the elements, indicating that, individually, no urgent action must be taken.
The beam elements showed the highest diversity of results, ranging from high integrity to critical, and from extremely low to high risk levels, with the majority concentrated at medium-high (35.1% of the elements) and medium (37.8% of the elements) risk levels.This result is mirrored in the risk level of the class, which is also the most diverse in the structure, ranging from "extremely low" to "medium".None of the beams were found to be of extremely high risk.In contrast, the slabs on Level 100 of Building i were found to be in a worse condition, containing the only family to present a "high" degree of risk and actions which must be taken within 3 months.As depicted above, most elements and classes fall under the "medium" or "medium-high" risk level, which is consistent with the observations made during the field evaluation.
Regarding the global structure, the Relevance Factor (F r ) applied to each family of elements are the ones shown on Table 10 It was assigned to the pillars on the ground floor, as they support more of the structure's load, a slightly greater weight than those on the first floor.
Therefore, the results for each class are the one on Table 11.
The fact that most column classes were classified as "medium-high" risk was certainly relevant to the result of the structure globally, which presented the same risk level classification.It means that the structure is not under urgent risk but should be under surveillance and actions should be taken within six months.In this surveillance, special attention must go to elements with high risk level, which would be the beams and slabs of level 100 of building i.The result is considered suitable according to the trained professionals who visited the work.In addition, again, when comparing with the other tested calibrations, the result is more accurate.

Modeling
The process of modeling a structure involves the generation of a three-dimensional virtual representation of the intended construction using specialized computational software.This approach offers the advantage of facilitating an in-depth visualization of the structural layers and details prior to the physical implementation of the design.In the context of the MAIS Method-Mode 1-the generation of structural elements is associated to their designated color coding according to the degree of risk specified in Table 6.The resulting 3D model of the structure can be observed in Fig. 10.This method offers significant benefits in terms of risk management, as it enables potential issues to be easily identified.This is a very simple and intuitive way of visualizing the degree of reliability of the elements and having an overview of the state of the structure.In the present case study, the region that contains L101, L102, V101A and V101B of the Building I, that presents red, is clearly the most critical one.

Conclusion
This research article presents a novel methodology, the Coupled Integrity and Safety Method (MAIS Method), for the structural evaluation of reinforced concrete.Through rigorous calibration and testing, an optimal formulation of the method was established.The results of the application of the MAIS Method to the construction of CLS 105 demonstrate that Heidecke's formulation and scale were found to be more suitable than Tuutti's, which were also evaluated.
One of the significant contributions of the MAIS Method is the utilization of a risk matrix, which allows for an intuitive and clear understanding of the results.The inclusion of guidelines and color-coding enhances the ease of identifying areas that require urgent intervention.
The findings of this study demonstrate that the MAIS Method produces consistent and accurate results that align with real-world conditions, highlighting its potential as a valuable tool for the structural evaluation of assets and properties.Further refinement and application of the MAIS Method are warranted to continue its development and implementation within the field of structural assessment.

)
Int c = 1 − D c , where D c : Class Damage.D em áx : Greater damage of element belonging to that class.D e : Element damage.n : Number of elements in the class Int c : Class integrity index.
F d : Damage Factor.F e : Extension Fac- tor.F i : Intensity Factor.: Reliability level.The minimum and maximum values of should follow the reference values for existing structures as shown in (10) ≈ Int F i , F d , F e , F r • ,

Fig. 8
Fig.8Risk level for the elements

Fig. 9
Fig.9Risk level for the class

Fig. 10
Fig. 10 Modeling associated with the reliability level of the element

Table 2
Relevance Factor Guide.a Sum of F r = 1.b Suggested values for F r

Table 3
Integrity classification

Table 5
MAIS risk matrix

Table 6
Risk classification of the structure and actions to take 83 Page 8 of 15

Table 7
Integrity and risk level of elements via MAIS method

Table 8
Integrity and risk level of classes via MAIS method

Table 9
Summary table of the risk level of elements and classes

Table 10
Applied relevance factor (F r ) on classes

Table 11
Global Integrity and Reliability via MAIS method