Inspection Planning Research Articles

PERFORMANCE OF INSPECTORATE IN SUPERVISION OF GOVERNMENT ADMINISTRATION IN BURU SELATAN REGENCY

This article investigated Performance of the Inspectorate in Supervision of Government Administration in Buru Selatan Regency. The type of study used was descriptive research. This would provide a factual depiction regarding the application of Inspectorate function of Buru Selatan Regency. This study aimed to analyze the performance of the Inspectorate in Supervision of Government Administration in Buru Selatan Regency. This study suggested that the application of supervision either perceived from the inspection, examination to investigation, in fact it had not been effectively worked due to the fact that inaccuracy in supervising and inaccurate aberration data were discovered for apparatus inspector in the office of Inspectorate. The factors affecting the performance of inspection function for government administration in Buru Selatan regency included the skilled apparatus officers having knowledge in the field of work of which they should tackle and facilities and infrastructure assisting the performance of inspection performed by the Inspectorate Office in Buru Selatan regency. The result suggested that the knowledge in the field of work was still low. It was suggested to implement the inspection planning functions for the purpose of supporting the speed in collecting data and accurate data/information presentation to date will support the reporting of any aberration arising in regional government administration, engage the officers in Human Resources development and the fulfillment of supporting facilitates and infrastructure.

Task allocation and coordinated motion planning for autonomous multi-robot optical inspection systems

Autonomous multi-robot optical inspection systems are increasingly applied for obtaining inline measurements in process monitoring and quality control. Numerous methods for path planning and robotic coordination have been developed for static and dynamic environments and applied to different fields. However, these approaches may not work for the autonomous multi-robot optical inspection system due to fast computation requirements of inline optimization, unique characteristics on robotic end-effector orientations, and complex large-scale free-form product surfaces. This paper proposes a novel task allocation methodology for coordinated motion planning of multi-robot inspection. Specifically, (1) a local robust inspection task allocation is proposed to achieve efficient and well-balanced measurement assignment among robots; (2) collision-free path planning and coordinated motion planning are developed via dynamic searching in robotic coordinate space and perturbation of probe poses or local paths in the conflicting robots. A case study shows that the proposed approach can mitigate the risk of collisions between robots and environments, resolve conflicts among robots, and reduce the inspection cycle time significantly and consistently.

Inspection planning by defect prediction models and inspection strategy maps

Designing appropriate quality-inspections in manufacturing processes has always been a challenge to maintain competitiveness in the market. Recent studies have been focused on the design of appropriate in-process inspection strategies for assembly processes based on probabilistic models. Despite this general interest, a practical tool allowing for the assessment of the adequacy of alternative inspection strategies is still lacking. This paper proposes a general framework to assess the effectiveness and cost of inspection strategies. In detail, defect probabilities obtained by prediction models and inspection variables are combined to define a pair of indicators for developing an inspection strategy map. Such a map acts as an analysis tool, enabling positioning assessment and benchmarking of the strategies adopted by manufacturing companies, but also as a design tool to achieve the desired targets. The approach can assist designers of manufacturing processes, and particularly low-volume productions, in the early stages of inspection planning.

Optimal adaptive inspection and maintenance planning for deteriorating structural systems

Optimizing inspection and maintenance (I&M) plans for a large deteriorating structure is a computationally challenging task, in particular if one considers interdependences among its components. This is due to the sheer number of possible decision alternatives over the lifetime of the structure and the uncertainty surrounding the deterioration processes, the structural performance and the outcomes of inspection and maintenance actions. To address this challenge, Luque and Straub (2019) proposed a heuristic approach in which I&M plans for structural systems are defined through a set of simple decision rules. Here, we formalize the optimization of these decision rules and extend the approach to enable adaptive planning. The initially optimal I&M plan is successively adapted throughout the service life, based on past inspection and monitoring results. The proposed methodology uses stochastic deterioration models and accounts for the interdependence among structural components. The heuristic-based adaptive planning is illustrated for a structural frame subjected to fatigue.

A two-stage optimization approach for inspection plan formulation of comprehensive inspection train: The China case

The regular and dynamic inspections of high-speed railways (HSR) are carried out by comprehensive inspection train (CIT). Generally, the network of HSR (e.g., the HSR network in China) has some obvious characteristics such as complex network structure, high traffic density and strict maintenance restrictions of CIT, which make the formulation of CIT inspection plan extremely hard. However, formulating and optimizing the CIT inspection plan is one of the key issues to ensure the safety of HSR operations and to improve the efficiency of testing equipment. In this paper, the original model is proposed for the multiple CITs inspection plan formulation problem (MCIT-IPFP) firstly, and it is proved that the problem belongs to the NP-hard class of computational complexity by reduction. By decomposing the problem into two stages, one is used to divide the HSR network evenly for each CIT, and the other one is used to generate the path, the timetable, and maintenance base assignment for each CIT under requirements of reducing the total time cost and the difficulty of solving. In order to improve the efficiency of calculation, a Constructive Heuristic Algorithm with feedback regulation based on the greedy algorithm is designed to generate the task division plan. With the purpose of quickly formulating the inspection plans with low time cost for each CIT with Euler circuit characteristics, a simulated annealing algorithm with efficient neighborhood Euler circuit generation strategy is proposed. Finally, a case study is conducted to test the efficiency of the algorithm by taking the China’s HSR network as the background. Compared with the previous manual inspection plan, the utilization rate of CITs will increase by 30%-50% when using the models and algorithms proposed in this paper.

Joint inspection and product quality optimization for a system with delayed failure

This paper proposes the integrated production, inspection, and quality planning of a machine with a two-stage delay time failure process (DTM). In a DTM, a failure proceeds with a potential defect. We assume a defective machine as one of the assignable causes of non-conforming products. The delay time is used as an opportunity to perform periodic quality control inspections of the products and detect higher than the acceptable level of non-conformity, which is an indicator of a defect in the machine. Before the arrival of a defect on the machine, the non-conforming products are produced with a contact rate. After a defect arrival, the proportion of non-conforming products increases with time until the machine failure or the detection of the defect at inspection. The reproduction of non-conforming products incurs extra penalty cost to the production. Moreover, in the case of higher than acceptable level of nonconformity, the defective machine is preventively replaced. If the machine fails, corrective replacement is carried out. We use a combination of stochastic mathematical formulation, simulation, and optimization to determine the optimal periodic inspection interval, which minimizes the total expected cost of the production. Several examples are provided to highlight some interesting aspects in the interactions between the production, quality, and maintenance.

On risk-based maintenance: A comprehensive review of three approaches to track the impact of consequence modelling for predicting maintenance actions

Since gas plants are progressively increasing near urban areas, a comprehensive tool to plan maintenance and reduce the risk arising from their operations is required. To this end, a comparison of three Risk-Based Maintenance methodologies able to point out maintenance priorities for the most critical components, is presented in this paper. Moreover, while the literature is mostly focused on probabilistic analysis, a particular attention is directed towards consequence analysis throughout this study. The first developed technique is characterized by a Hierarchical Bayesian Network to perform the occurrence analysis and a Failure Modes, Effects and Criticality Analysis to assess the magnitude of the adverse outcomes. The second approach is a Quantitative Risk Analysis carried out via a software named Safeti. Finally, another software called Synergi Plant is adopted for the third methodology, which provides a Risk-Based Inspection plan, through a semiquantitative risk analysis. The proposed study can assist asset manager in adopting the most appropriate methodology to their context, while highlighting priority components. To demonstrate the applicability of the approaches and compare their rankings, a Natural Gas Regulating and Measuring Station is considered as case study. The results showed that the most suited method strongly depends on the available data.

Risk-Based InspectionTechnique and Critical Success Factors in its Implementation to Improve Risk and Process Safety-Based Management Systems: A review study

Introduction: Risk-based inspection is a powerful tool provided by the American Petroleum Institute in order to respond to the needs of the process industries. The main focus of this method is on inspection, integrity management, maintenance, as well as reduction of the probability of failure. The purpose of this study was to conduct the risk-based inspection technique and critical success factors in its implementation to improve risk and process safety based management systems.
 Methods: In this review study, we first listed the keywords based on the research title including Critical Success Factors, risk assessment, process safety, corrosion management, inspection Plan, failure mechanism, Risk Based Inspection, Risk Based Maintenance, Risk-based Integrity Management, and Asset Integrity Management. Later, each term was searched specifically and without time limit in the internal and external databases of Science Direct, PubMed, Google Scholar, SID, Google Search, Magiran, Civilica, and Scopus.
 Result: A systematic review of various studies showed that critical success factors provided the necessary context for the implementation of a risk-based inspection process in the process industries and were essential factors for the effective implementation of the RBI method.
 Conclusion: By analyzing the results of the studies we found that identifying CSFs can improve the effective implementation of RBI in industries and guarantee the benefits mentioned for this method. Moreover, the engineering and accurate implementation of risk-based inspection method will lead to the best implementation of management systems based on the risk and process safety and its improvement.

Coordinated approaches for port state control inspection planning

ABSTRACT Port state control (PSC) inspections serve to guard maritime safety and the marine environment. Because port inspection resources are limited, inspection efficiency can be improved if the resources are scheduled more efficiently. Currently, ports worldwide apply a greedy inspection strategy. To improve inspection efficiency, this study proposes two coordinated inspection strategies for both liner and tramp ships, i.e., a self-coordinated port strategy and a fully coordinated central agent strategy. Extensive numerical experiments indicate that on average the self-coordinated port strategy performs 2.48% better than the greedy strategy, and the fully coordinated strategy outperforms the greedy and self-coordinated port strategies by 5.02% and 2.48%, respectively. The superiority of the two coordinated strategies is robust to different ratios of liner to tramp ships visiting the ports from 0/100 to 100/0. Therefore, the feasibility and wide applicability of the proposed coordinated strategies are validated. Specifically, when liner ships outnumber tramp ships, the fully coordinated strategy is more suitable; otherwise, both the self-coordinated port strategy and the fully coordinated strategy can be used.

Modeling of interaction between shareholders and control bodies

The article deals with the problem of organization of financial control procedures for the activities of a joint-stock company by the audit bodies. The development of effective verification mechanisms can significantly reduce the cost of conducting them and increase their effectiveness. One of the problems that arise in the study of such problems is the modeling of behavior of participants in the system of internal and external control. The solution of this problem is impossible without the use on a scientific basis of economic and mathematical models of financial control mechanisms, taking into account the economic relations of the subjects and the object of control, allowing to assess the costs of control and its effectiveness. The article examines the mechanism of interaction between shareholders and control bodies. Models describing this interaction have been developed, as well as the tasks of determining the vector of the planned task of inspections by control bodies have been formulated and solved. The parameters of the verification procedure are determined by the criterion of maximizing the economic effect of the center from conducting inspections by the control bodies. The model uses a multiplicative function of the economic effect of the center on the possession of information on each of the subjects of control. The members of the system are the audit commission, the board of directors and the audit organization. For each participant of the system, target functions are formulated, taking into account information about material remuneration and taking into account alternative income. The developed model is tested on numerical data on the cost of conducting inspections and on alternative income. The results of the calculations illustrate the behavior patterns of the system participants, in particular, the feasibility of paying the full cost of inspections by the center and the implementation of the inspection plan by the control bodies in the appropriate volume.

Oil Tanker Simplified Fatigue Assessment with Inspection and Repair Approach and Parameters

The occurrence of cracks in the hull structure of oil tankers is an important concern for the maritime industry because crack propagation will reduce collapse strength of deck-stiffened panels and, consequently, decrease the ultimate hull girder capacity of ship’s structures. Fatigue is an important design criteria for ships to ensure a sufficiently high safety level. Fatigue life predictions of ship’s structural details have traditionally been carried out using S-N approach and the Palmgren-Miner’s rule. The principal objective of such approach is to estimate the time to failure in order to ensure a satisfactory design lifetime of ship’s structural components. Potential cracks are considered to occur in the side shell, in the connections between longitudinal stiffeners and transverse web frame. The main objectives of the present study are to evaluate the fatigue life of vessel’s amidships using the simplified fatigue method, which is based on DNVGL-CG-0129 “Fatigue Assessment of Ship Structures” in order to determine the main cause of the observed cracks on the single skin oil tanker. Fatigue assessment was based on worldwide trade. Longitudinal stiffeners at transverse frames amidships are considered. The results show that fatigue life is generally above 20 years; however, analysis has revealed that the fatigue life of typical stiffener transitions in the side shell is below 20 years. The fatigue lives of side shell longitudinals are regarded as normal for ships built in the period between 1980 and 1990 with extensive use of high tensile steel in the side shell. Inspection and repair proposals of details with fatigue lives below 20 years are advised accordingly. Findings of fatigue analyses provide remaining life assessment, inspection plan definition, determination of repair and modification solutions, and avoiding integrity issues resulting in production downtime and hot work or dry dock.

A Blended Two-Sided Chain Sampling Plan Created on Process Potential Measure

This research article presents, a blended two-sided chain inspection plan with process potential measure. The Probability of acceptance and related measures are shown. Tables are prepared to find the parameters of the plan. In this plan the variable inspection sample size is obtained by using normal distribution and in the attribute inspection, two-sided chain sampling plan which yields small sample size is used the designed sampling plan is really used in production industries to study the product with respect to the specification measures and to defend the period and charge of inspection to impact on the end product.

The Role of Probability Distributions in Establishing Acceptance Sampling Plans and Quality Control Charts

This paper aims at identifying the probability distributions used in controlling the quality of products of industrial companies by examining the degree of the probability distributions' efficient in strengthen the control process that, consequently, would lead companies to cope with the new technologies to overcome the difficulties and problems they counter in controlling the quality of their products. This study used discrete and continuous probability distributions and explained how they can be used in acceptance inspection plans and quality control charts by examining the inputs and outputs of the production process and the production process itself. The results of this study indicated to the use of probability distributions maintains continuous improvement in quality and checks for convergence between inputs and outputs. In addition, the use of probability distributions enhances the efficiency and effectiveness of quality control. The results of this study are of importance to managements in the manufactured companies concerning the significance of using probability distributions to control the quality of products at all stages of production. Moreover, the establishment of periodical training programs specialized in quality control, with a focus on the use of probability distributions.

Risk-based inspection planning of deteriorating structures

Structural deterioration due to environmental and mechanical stressors is a major concern for civil and marine structures. Inspection actions can reduce uncertainties, facilitate decision-making on maintenance, and in general assist life-cycle management. Risk-based inspection (RBI) planning is a useful tool to minimize life-cycle cost while preserving safety margin of structures. This paper compares (a) static RBI (SRBI) planning where inspection schedule and maintenance criteria are time- and evidence-invariant and (b) adaptive RBI (ARBI) planning where decisions on inspection and maintenance (I&M) are made sequentially and reactively to I&M actions. Specifically, three RBI planning methods, i.e., SRBI with Monte Carlo simulation, ARBI based on Bayesian networks, and ARBI based on partially observable Markov decision processes (POMDP), are compared based on a generic Markovian deterioration model (MDM). In addition, it is demonstrated that ARBI planning can be extended from MDMs to many physics-based deterioration models such as corrosion and fatigue models. The advantages and disadvantages of different RBI planning methods are summarized. Potentials of ARBI planning are also discussed.

Beekeeping Potential, Richness, and Distribution of Plant Species Foraged by Stinging Honey Bee (Apis Mellifera L.) in West Kilimanjaro Tanzania Forest Service Agency (TFS) Plantation.

An assessment of beekeeping potential, richness, and distribution of plant species foraged by stinging honey bee Apis mellifera L. in West Kilimanjaro Tanzania Forest Service Agency (TFS) Plantation area was conducted in 2020. A total of 40, 20 m x 20 m plots were set on the 5 natural vegetation remnants within the plantation forest ranges of Sanya juu, Lemosho, Hill wood, Wasendo, and Londrosi at an interval of 100 m. Within the 20 m x 20 m, 1 m x 1 m nested plots were established to assess herbs, sedge, grasses, and seedlings, while 2 m x 5 m were established to determine shrubs. Agriculture crops grown by the bordering villagers were identified and evaluated for the bee forage potential. Plant species richness (S) was determined from the total number of plant species identified from every site using the Shannon Weiner Diversity Index (H’). Plant species distribution was determined grounded on the frequency (F) and evenness (E) were determined. The sites were revealed to have high plant species diversity foraged by stinging honey bees. A total of 204 plant species belonging to 76 families and 178 genera were identified. The calculates H’ of 2.37 for non-wood plants and 3.05 for wood plants implied high plant diversity. The most distributed plant species had a relative frequency (RF) of 6.250 ± 3.0303, while the rest had an RF < 3.0303. The disappearance of one species does not cause any significant effect on bees, as they can go for another species in the area. 92% of non-woody plants and 94% of the identified woody plants were known to be foraged by stinging honey bees. The evenness (E) of 0.7484 for non-wood plants and 0.795 implied that the plants in all categorize were not evenly distributed. West Kilimanjaro Forest Plantation (WKFP) natural forest patches are potential for honey beekeeping. Stinging honey bee fodder plants should be planted, regular visits to the project sites should be exercised to protect honey theft, spot clearing to give a room for naturally germinated seedlings covered by climbers. Further study should be done on the biological species diversity, training to beekeeping staff, and plan for regular inspection of the honey bee colony strength will help to reveal any challenges facing the venture including diseases and hives strengths and weakness.

Evaluation of in-service power transformer health condition for Inspection, Repair, and Replacement (IRR) maintenance planning in electric utilities

Evaluation of in-service power transformer health condition for Inspection, Repair, and Replacement (IRR) maintenance planning in electric utilities

Deep reinforcement learning driven inspection and maintenance planning under incomplete information and constraints

Determination of inspection and maintenance policies for minimizing long-term risks and costs in deteriorating engineering environments constitutes a complex optimization problem. Major computational challenges include the (i) curse of dimensionality, due to exponential scaling of state/action set cardinalities with the number of components; (ii) curse of history, related to exponentially growing decision-trees with the number of decision-steps; (iii) presence of state uncertainties, induced by inherent environment stochasticity and variability of inspection/monitoring measurements; (iv) presence of constraints, pertaining to stochastic long-term limitations, due to resource scarcity and other infeasible/undesirable system responses. In this work, these challenges are addressed within a joint framework of constrained Partially Observable Markov Decision Processes (POMDP) and multi-agent Deep Reinforcement Learning (DRL). POMDPs optimally tackle (ii)-(iii), combining stochastic dynamic programming with Bayesian inference principles. Multi-agent DRL addresses (i), through deep function parametrizations and decentralized control assumptions. Challenge (iv) is herein handled through proper state augmentation and Lagrangian relaxation, with emphasis on life-cycle risk-based constraints and budget limitations. The underlying algorithmic steps are provided, and the proposed framework is found to outperform well-established policy baselines and facilitate adept prescription of inspection and intervention actions, in cases where decisions must be made in the most resource- and risk-aware manner.

انتخاب هم‌زمان تأمین‌کنندگان و تعیین سیاست موجودی زنجیره‌های تأمین غیرقطعی چندمحصولی با رویکرد بهینه‌سازی مبتنی بر شبیه‌سازی

I‌n‌c‌r‌e‌a‌s‌i‌n‌g b‌u‌s‌i‌n‌e‌s‌s c‌o‌m‌p‌e‌t‌i‌t‌i‌v‌e‌n‌e‌s‌s f‌o‌r‌c‌e‌d c‌o‌m‌p‌a‌n‌i‌e‌s t‌o i‌m‌p‌r‌o‌v‌e t‌h‌e‌i‌r b‌u‌s‌i‌n‌e‌s‌s. T‌h‌e‌r‌e‌f‌o‌r‌e, i‌n‌d‌u‌s‌t‌r‌y m‌a‌n‌a‌g‌e‌r‌s h‌a‌v‌e f‌o‌u‌n‌d t‌h‌a‌t i‌t i‌s n‌e‌c‌e‌s‌s‌a‌r‌y t‌o f‌o‌c‌u‌s o‌n t‌h‌e s‌u‌p‌p‌l‌y o‌f p‌r‌o‌d‌u‌c‌t‌s i‌n a‌c‌c‌o‌r‌d‌i‌n‌g t‌o t‌h‌e w‌i‌s‌h‌e‌s o‌f t‌h‌e c‌u‌s‌t‌o‌m‌e‌r t‌h‌e q‌u‌a‌l‌i‌t‌y a‌n‌d t‌h‌e c‌o‌s‌t o‌f t‌h‌e‌i‌r i‌n‌t‌e‌n‌d‌e‌d u‌s‌e. W‌e c‌o‌n‌s‌i‌d‌e‌r a t‌h‌r‌e‌e-s‌t‌a‌g‌e s‌u‌p‌p‌l‌y c‌h‌a‌i‌n i‌n‌v‌o‌l‌v‌i‌n‌g m‌u‌l‌t‌i‌p‌l‌e s‌u‌p‌p‌l‌i‌e‌r‌s, m‌a‌n‌u‌f‌a‌c‌t‌u‌r‌e‌r p‌r‌o‌d‌u‌c‌i‌n‌g m‌u‌l‌t‌i‌p‌l‌e t‌y‌p‌e o‌f p‌r‌o‌d‌u‌c‌t a‌n‌d a f‌i‌n‌a‌l c‌u‌s‌t‌o‌m‌e‌r. A‌t e‌a‌c‌h o‌r‌d‌e‌r, t‌h‌e m‌a‌n‌u‌f‌a‌c‌t‌u‌r‌e‌r r‌e‌c‌e‌i‌v‌e‌s t‌h‌e r‌a‌w m‌a‌t‌e‌r‌i‌a‌l f‌r‌o‌m a s‌u‌p‌p‌l‌i‌e‌r b‌a‌s‌e‌d o‌n o‌p‌t‌i‌m‌a‌l p‌o‌l‌i‌c‌y i‌n a l‌o‌t o‌f s‌i‌z‌e Q. T‌h‌e p‌r‌o‌d‌u‌c‌t‌i‌o‌n p‌r‌o‌c‌e‌s‌s c‌o‌u‌l‌d p‌r‌o‌d‌u‌c‌e a‌d‌d‌i‌t‌i‌o‌n‌a‌l n‌o‌n‌c‌o‌n‌f‌o‌r‌m‌i‌n‌g p‌r‌o‌d‌u‌c‌t‌s, t‌h‌e m‌a‌n‌u‌f‌a‌c‌t‌u‌r‌e‌r c‌o‌u‌l‌d b‌e u‌n‌a‌v‌a‌i‌l‌a‌b‌l‌e d‌u‌e t‌o f‌a‌i‌l‌u‌r‌e‌s (f‌o‌l‌l‌o‌w‌i‌n‌g a g‌e‌n‌e‌r‌a‌l t‌i‌m‌e-t‌o f‌a‌i‌l‌u‌r‌e d‌i‌s‌t‌r‌i‌b‌u‌t‌i‌o‌n), a‌n‌d r‌e‌p‌a‌i‌r o‌p‌e‌r‌a‌t‌i‌o‌n‌s (f‌o‌l‌l‌o‌w‌i‌n‌g a g‌e‌n‌e‌r‌a‌l t‌i‌m‌e-t‌o-r‌e‌p‌a‌i‌r d‌i‌s‌t‌r‌i‌b‌u‌t‌i‌o‌n) p‌r‌o‌p‌o‌s‌e a c‌o‌n‌t‌r‌o‌l p‌o‌l‌i‌c‌y, w‌h‌i‌c‌h c‌o‌o‌r‌d‌i‌n‌a‌t‌e‌s s‌u‌p‌p‌l‌i‌e‌r s‌e‌l‌e‌c‌t‌i‌o‌n, r‌e‌p‌l‌e‌n‌i‌s‌h‌m‌e‌n‌t, p‌r‌o‌d‌u‌c‌t‌i‌o‌n a‌n‌d q‌u‌a‌l‌i‌t‌y i‌n‌s‌p‌e‌c‌t‌i‌o‌n d‌e‌c‌i‌s‌i‌o‌n‌s. U‌p‌o‌n r‌e‌c‌e‌p‌t‌i‌o‌n, t‌h‌e m‌a‌n‌u‌f‌a‌c‌t‌u‌r‌e‌r a‌p‌p‌l‌i‌e‌s a s‌i‌m‌p‌l‌e l‌o‌t-b‌y-l‌o‌t a‌c‌c‌e‌p‌t‌a‌n‌c‌e-s‌a‌m‌p‌l‌i‌n‌g p‌l‌a‌n w‌i‌t‌h a‌t‌t‌r‌i‌b‌u‌t‌e‌s. T‌h‌i‌s p‌l‌a‌n i‌s c‌h‌a‌r‌a‌c‌t‌e‌r‌i‌z‌e‌d b‌y a r‌a‌n‌d‌o‌m s‌a‌m‌p‌l‌e o‌f s‌i‌z‌e n a‌n‌d a‌n a‌c‌c‌e‌p‌t‌a‌n‌c‌e c‌r‌i‌t‌e‌r‌i‌o‌n c. B‌a‌s‌e‌d o‌n t‌h‌i‌s i‌n‌s‌p‌e‌c‌t‌i‌o‌n p‌l‌a‌n i‌f t‌h‌e n‌u‌m‌b‌e‌r o‌f n‌o‌n-c‌o‌n‌f‌o‌r‌m‌i‌n‌g i‌t‌e‌m‌s d f‌o‌u‌n‌d i‌n t‌h‌i‌s s‌a‌m‌p‌l‌e i‌s e‌q‌u‌a‌l t‌o o‌r l‌e‌s‌s t‌h‌a‌n c t‌h‌e l‌o‌t w‌i‌l‌l b‌e a‌c‌c‌e‌p‌t‌e‌d. O‌t‌h‌e‌r‌w‌i‌s‌e, t‌h‌e l‌o‌t w‌i‌l‌l b‌e r‌e‌f‌u‌s‌e‌d a‌n‌d r‌e‌t‌u‌r‌n‌e‌d t‌o i‌t‌s o‌r‌i‌g‌i‌n‌a‌l s‌u‌p‌p‌l‌i‌e‌r a‌n‌d t‌h‌e‌n a n‌e‌w o‌r‌d‌e‌r i‌s p‌l‌a‌c‌e‌d. A‌t t‌h‌i‌s i‌n‌s‌t‌a‌n‌t t‌h‌e m‌a‌n‌u‌f‌a‌c‌t‌u‌r‌e‌r i‌s n‌o‌t o‌b‌l‌i‌g‌e‌d t‌o k‌e‌e‌p t‌h‌e s‌a‌m‌e s‌u‌p‌p‌l‌i‌e‌r. H‌e c‌a‌n c‌h‌o‌o‌s‌e a‌n‌y o‌n‌e t‌h‌a‌t o‌f‌f‌e‌r‌s b‌e‌t‌t‌e‌r r‌e‌p‌l‌e‌n‌i‌s‌h‌m‌e‌n‌t c‌o‌n‌d‌i‌t‌i‌o‌n‌s. I‌n t‌h‌i‌s w‌o‌r‌k. w‌e a‌i‌m t‌o d‌e‌t‌e‌r‌m‌i‌n‌e t‌h‌e o‌p‌t‌i‌m‌a‌l c‌o‌n‌t‌r‌o‌l p‌o‌l‌i‌c‌y f‌o‌r s‌u‌p‌p‌l‌i‌e‌r s‌e‌l‌e‌c‌t‌i‌o‌n r‌e‌p‌l‌e‌n‌i‌s‌h‌m‌e‌n‌t a‌n‌d o‌p‌t‌i‌m‌a‌l q‌u‌a‌l‌i‌t‌y c‌o‌n‌t‌r‌o‌l d‌e‌c‌i‌s‌i‌o‌n‌s t‌h‌a‌t m‌i‌n‌i‌m‌i‌z‌e‌s t‌h‌e t‌o‌t‌a‌l c‌o‌s‌t w‌h‌i‌c‌h i‌n‌c‌l‌u‌d‌e‌s i‌n‌v‌e‌n‌t‌o‌r‌y, b‌a‌c‌k‌l‌o‌g, i‌n‌s‌p‌e‌c‌t‌i‌o‌n, r‌e‌p‌l‌e‌n‌i‌s‌h‌m‌e‌n‌t a‌n‌d p‌r‌o‌d‌u‌c‌t‌i‌o‌n c‌o‌s‌t‌s. C‌o‌o‌r‌d‌i‌n‌a‌t‌i‌n‌g d‌e‌c‌i‌s‌i‌o‌n‌s a‌l‌o‌n‌g t‌h‌e e‌n‌t‌i‌r‌e c‌h‌a‌i‌n i‌s c‌r‌i‌t‌i‌c‌a‌l s‌i‌n‌c‌e i‌t r‌e‌q‌u‌i‌r‌e‌s d‌e‌t‌e‌r‌m‌i‌n‌i‌n‌g c‌a‌r‌e‌f‌u‌l‌l‌y w‌h‌a‌t t‌o m‌a‌n‌u‌f‌a‌c‌t‌u‌r‌e a‌s w‌e‌l‌l a‌s w‌h‌a‌t w‌h‌e‌n a‌n‌d f‌r‌o‌m w‌h‌o‌m t‌o o‌r‌d‌e‌r. S‌o s‌i‌m‌u‌l‌a‌t‌i‌o‌n-b‌a‌s‌e‌d o‌p‌t‌i‌m‌i‌z‌a‌t‌i‌o‌n i‌s o‌n‌e o‌f t‌h‌e m‌e‌t‌h‌o‌d‌s f‌o‌r s‌o‌l‌v‌i‌n‌g t‌h‌i‌s p‌r‌o‌b‌l‌e‌m. N‌u‌m‌e‌r‌i‌c‌a‌l e‌x‌a‌m‌p‌l‌e‌s s‌h‌o‌w t‌h‌e e‌f‌f‌i‌c‌i‌e‌n‌c‌y o‌f t‌h‌e p‌r‌o‌p‌o‌s‌e‌d m‌e‌t‌h‌o‌d.

Digital Twin Aided Vulnerability Assessment and Risk-Based Maintenance Planning of Bridge Infrastructures Exposed to Extreme Conditions

Over the past centuries, millions of bridge infrastructures have been constructed globally. Many of those bridges are ageing and exhibit significant potential risks. Frequent risk-based inspection and maintenance management of highway bridges is particularly essential for public safety. At present, most bridges rely on manual inspection methods for management. The efficiency is extremely low, causing the risk of bridge deterioration and defects to increase day by day, reducing the load-bearing capacity of bridges, and restricting the normal and safe use of them. At present, the applications of digital twins in the construction industry have gained significant momentum and the industry has gradually entered the information age. In order to obtain and share relevant information, engineers and decision makers have adopted digital twins over the entire life cycle of a project, but their applications are still limited to data sharing and visualization. This study has further demonstrated the unprecedented applications of digital twins to sustainability and vulnerability assessments, which can enable the next generation risk-based inspection and maintenance framework. This study adopts the data obtained from a constructor of Zhongcheng Village Bridge in Zhejiang Province, China as a case study. The applications of digital twins to bridge model establishment, information collection and sharing, data processing, inspection and maintenance planning have been highlighted. Then, the integration of “digital twins (or Building Information Modelling, BIM) + bridge risk inspection model” has been established, which will become a more effective information platform for all stakeholders to mitigate risks and uncertainties of exposure to extreme weather conditions over the entire life cycle.

A Comprehensive Uncertainty-Based Framework for Inspection Planning of Highway Bridges

Bridge inspection standards in the United States require routine visual inspections to be conducted on most bridges at a maximum interval of two years regardless of the bridge condition. Limitations of this uniform calendar-based approach have been reported in the literature. Accordingly, the objective of this study is to provide a new systematic approach for inspection planning that integrates information from bridge condition prediction models, inspection data, and expert opinion using Bayesian analysis to enhance inspection efficiency and maintenance activities. The uncertainty-based inspection framework proposed in this study can help bridge owners avoid unnecessary or delayed inspections and repair actions, determine the inspection method, and consider more than one deterioration process or bridge component during the inspection planning process. The inspection time and method are determined based on the uncertainty and risks associated with the bridge condition. As uncertainty in the bridge condition reaches a defined threshold, an inspection is scheduled utilizing nondestructive techniques to reduce the uncertainty level. The framework is demonstrated on a new and on an existing reinforced concrete bridge deck impacted by corrosion deterioration. The results show that the framework can reduce the number of inspections by 50% compared to conventional scheduling methods, and the uncertainty regarding the bridge maintenance time is reduced by 16%.