Causes Of Operational Failures Research Articles

A Strategic Approach to Mitigating Operational Failure Across Transitions

It is recognized that projects continue to deliver operational assets that are partially defective. This article proposes this because the causes of operational failures have not been extensively analyzed. This study explores how an infrastructure client made quality a strategic and project delivery necessity by undertaking research to analyze operational failure. A mixed-method approach consisting of three phases was used: (1) to understand the operational failure elements; (2) to explore the causes of operational failure; and (3) to develop a new strategic framework to address failure mitigation. The study showed the need for transferring, applying, and recognizing capabilities across strategic business, project delivery, and operational use transitions.

RESTORATION OF THE CONSTRUCTION AND ROAD MACHINES’ DETAILS FROM GREY CAST IRON: IMPROVEMENT OF THE REPAIR DIMENSIONS’ METHOD EFFICIENCY

Introduction. The total mass of some grey cast iron details in construction and road machines reaches 60%. Cylinder blocks, parts of braking systems, flywheels, etc. are made of cast-iron. One of the main causes of operational failures (up to 70%) of construction and road machines is failure of friction units. Considering that the contacting parts in these units take the load mainly by surface layers. The operability looses at relatively small values of dimensional wear. Although mass wear of the part usually does not exceed 1%.Materials and methods. The authors carried out a comprehensive technical and economic analysis of repair methods of friction assemblies. As a result, the best combination of criteria was the repair size method. However, the strengthened layer was removed to the repair dimension by conventional reconditioning technology. At the same time grey cast iron was strengthened only by very expensive and labor-intensive methods, which in conditions of real repair production were not applicable. The authors considered the possibility of using a new method of strengthening iron parts in repair works.Results. The developed method strengthened grey cast iron with layer thickness up to 3 mm. The distinctive feature was that hardness of the strengthened layer in thickness increased. At the same time the microhardness increased in comparison with the initial grey iron more than 2 times and wear resistance became comparable to high-strength hardened stun.Discussion and conclusions. The authors obtain the best results with the usage of reducing atmosphere furnaces. In order to expand the scope of the method, the researches proposed to use a special device creating the necessary conditions in any furnace. The application of the proposed technical solutions increases the efficiency of the construction and road machines’ repair.The authors have read and approved the final manuscript. Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.

Improving the competitiveness of mechanical engineering

The low level of competitiveness of Russian machinery and equipment is due, first of all, to an insufficient level of workmanship and reliability indicators. In terms of technical characteristics, the level of resource saving, the implementation of modern technological methods and methods for the manufacturing of products, works and services, many models of modern machinery are not inferior, and often surpass foreign analogues. But the low level of reliability indicators and, above all, the reliability of machines in the end significantly reduce the efficiency of its use in real production and economic conditions of consumers of equipment. The work is aimed at searching and substantiating directions for improving the quality of manufacturing and reliability indicators of domestic machinery and equipment based on the creation of proprietary production and technological systems and complexes and the introduction of a proprietary method of technical service. Improving the quality of Russian equipment on an innovative organizational and technological basis will ensure the necessary technological breakthrough in mechanical engineering with the minimum needs of production and technical resources in a short time. Studies indicate the need to reorganize engineering enterprises into large firms, branded production and technological systems and complexes that can provide a sharp and significant increase in the quality of equipment to the level of the best world analogues. The organization of large engineering companies allows solving the quality problems of machinery and equipment at all the main stages of their life cycle: design, construction, production, operation and disposal. At the same time, the efficiency of resolving emerging issues is significantly increased, since all structural divisions of the company are managed from a single center, whose strategic goal is to comprehensively improve the quality of engineering products. A quick and significant increase in the competitiveness of domestic machinery and equipment based on an increase in their manufacturing quality and reliability indicators is possible only with the introduction of their proprietary technical service. The company service system will allow establishing and excluding the causes of operational failures of machinery.

Designed for workarounds: a qualitative study of the causes of operational failures in hospitals.

Frontline care clinicians and staff in hospitals spend at least 10% of their time working around operational failures: situations in which information, supplies, or equipment needed for patient care are insufficient. However, little is known about underlying causes of operational failures and what hospitals can do to reduce their occurrence. To address this gap, we examined the internal supply chains at 2 hospitals with the aim of discovering organizational factors that contribute to operational failures. We conducted in-depth qualitative research, including observations and interviews of more than 80 individuals from 4 nursing units and the ancillary support departments that provide equipment and supplies needed for patient care. We found that a lack of interconnectedness among interdependent departments' routines was a major source of operational failures. The low levels of interconnectedness occurred because of how the internal supply chains were designed and managed rather than because of employee error or a shortfall in training. Thus, we propose that the time that hospital staff members spend on workarounds can be reduced through deliberate efforts to increase interconnectedness among hospitals' internal supply departments. Four dimensions of interconnectedness include: 1) hospital-level-rather than department-level-performance measures; 2) internal supply department routines that respond to specific patients' needs rather than to predetermined stocking routines; 3) knowledge that is necessary for efficient handoffs of materials that is translated across departmental boundaries; and 4) cross-departmental collaboration mechanisms that enable improvement in the flow of materials across departmental boundaries.

The Small Abnormal Parathyroid Gland is Increasingly Common and Heralds Operative Complexity

Over decades, improvements in presymptomatic screening and awareness of surgical benefits have changed the presentation and management of primary hyperparathyroidism (PHPT). Unrecognized multiglandular disease (MGD) remains a major cause of operative failure. We hypothesized that during parathyroid surgery the initial finding of a mildly enlarged gland is now frequent and predicts both MGD and failure. A prospective database was queried to examine the outcomes of initial exploration for sporadic PHPT using intraoperative PTH monitoring (IOPTH) over 15 years. All patients had follow-up ≥6 months (mean = 1.8 years). Cure was defined by normocalcemia at 6 months and microadenoma by resected weight of <200 mg. Of the 1,150 patients, 98.9 % were cured and 15 % had MGD. The highest preoperative calcium level decreased over time (p < 0.001) and varied directly with adenoma weight (p < 0.001). Over time, single adenoma weight dropped by half (p = 0.002) and microadenoma was increasingly common (p < 0.01). MGD risk varied inversely with weight of first resected abnormal gland. Microadenoma required bilateral exploration more often than macroadenoma (48 vs. 18 %, p < 0.01). When at exploration the first resected gland was <200 mg, the rates of MGD (40 vs. 11 %, p = 0.001), inadequate initial IOPTH drop (67 vs. 79 %, p = 0.002), operative failure (6.6 vs. 0.7 %, p < 0.001), and long-term recurrence (1.6 vs. 0.3 %, p = 0.007) were higher. Single parathyroid adenomas are smaller than in the past and require more complex pre- and intraoperative management. During exploration for sporadic PHPT, a first abnormal gland <200 mg should heighten suspicion of MGD and presages a tenfold higher failure rate.

Operative Failure in Minimally Invasive Parathyroidectomy Utilizing an Intraoperative Parathyroid Hormone Assay

Minimally invasive parathyroidectomy (MIP) is a targeted operation to cure primary hyperparathyroidism utilizing intraoperative parathyroid hormone monitoring (IOPTH). The purpose of this study was to quantify the operative failure of MIP. Utilizing institutional parathyroid surgery database, demographic, operative, and biochemical data were analyzed for successful and failed MIP. Operative failure was defined as <6months of eucalcemia after operation. Five hundred thirty-eight patients (96.6%) had successful MIP with mean follow-up of 13months, and 19 (3.4%) had operative failure. The major cause of operative failure (11 of 19) was the result of surgeons' inability to identify all abnormal parathyroid glands. The remaining eight operative failures were the result of falsely positive IOPTH results. Eleven of 19 patients whose MIP had failed underwent a second parathyroid surgery. All but one of these patients achieved operative success, and 9 patients had missed multigland disease. Only 46 (8.3%) of 557 patients had conversion to bilateral cervical exploration (BCE). Eighty percent of patients had more than 70% IOPTH decrease, and all had successful operations. Patients with a marginal IOPTH decrease (50-59%) had a treatment failure rate of 20%. The most common cause of operative failure in MIP utilizing IOPTH was the result of surgeons' failure to identify all abnormal parathyroid glands. Falsely positive IOPTH is rare, and a targeted MIP utilizing IOPTH can achieve an excellent operative success rate without routine BCE. Selective BCE on patients with marginal IOPTH decrease may improve surgical outcome.

Typowe przyczyny uszkodzeń eksploatacyjnych transformatorów energetycznych

Typical causes of operational failures in power transformers working in National Grid are presented in the paper. The main reasons for these failures have been discussed on the basis of post-failure transformer tests run during last 20 years. The failure statistics has constituted the grounds for making a list of typical failures and indicating transformer groups characterized by highest failure rates. The selected examples of power transformers' typical failures have been demonstrated, caused by damages to insulation systems, bushings. and on-load tap changers (OLTCs). Typical causes of operational failures in power transformers working in National Grid

Defining failure after parathyroidectomy for primary hyperparathyroidism: case series

To identify the cause of operative failure in patients who have undergone parathyroid surgery for primary hyperparathyroidism. Retrospective case review. Patients who had undergone a primary procedure for primary hyperparathyroidism between July 2003 and December 2007. Cases with incomplete post-operative serum calcium data were excluded. Operative failure was defined as failure to achieve normalisation of serum adjusted calcium levels post-operatively. A total of 220 primary procedures were conducted over 4.5 years. Data were not available for 16 patients. Thirteen procedures (6.4 per cent) were considered failures, and these cases were individually reviewed and classified according to the reason for failure. Establishing the cause of failure following surgery for primary hyperparathyroidism can be a complex task. In some instances, diagnostic uncertainty remains despite detailed biochemical and radiological assessment. This paper outlines our approach to maximising the cure rate at primary surgery.

Operative Failure in the Era of Focused Parathyroidectomy

Focused parathyroidectomy guided by intraoperative parathyroid hormone monitoring (IPM) may lead to higher failure rates because of missed multiglandular disease. Retrospective review of prospectively collected data. Tertiary referral center. From September 8, 1993, through January 30, 2009, a total of 845 consecutive patients with sporadic primary hyperparathyroidism underwent focused parathyroidectomy guided by IPM at a single institution. Parathyroid hormone dynamics and perioperative data were analyzed for factors affecting outcome. Operative failure was defined as hypercalcemia with elevated parathyroid hormone levels within 6 months after parathyroidectomy. Detailed intraoperative data from the failed operations were also reviewed. Of 723 patients followed up for at least 6 months, 702 (97.1%) had successful parathyroidectomy, and 21 (2.9%) had failed parathyroidectomy. The major cause of operative failure was the surgeon's inability to find the abnormal parathyroid gland (16 of 21 patients [76.2%]). In the remaining patients, IPM results were false-positive in 5 of 21 patients (23.8%) or 0.7% overall. Among the cohort, IPM correctly identified missed multiglandular disease in 33 of 38 patients (86.8%). Patients having operative failure were more likely to have a history of thyroidectomy or parathyroidectomy and were less likely to have correct findings on technetium Tc 99m sestamibi or ultrasonographic localizing studies compared with patients having operative success. Inability of the surgeon to find the abnormal parathyroid gland-not missed multiglandular disease-is the main cause of operative failure in focused parathyroidectomy guided by IPM.

Section 1. Parathyroid: Intraoperative quick parathyroid hormone assay in the surgical management of hyperparathyroidism

Intraoperative quick parathyroid hormone (QPTH) assay is claimed to prevent failure during parathyroidectomy for hyperparathyroidism. The causes of operative failure have included multiglandular disease, ectopic parathyroid glands, supernumerary parathyroid glands, errors in frozen section evaluations, and missed diagnosis. A QPTH assay has been recognized as a useful method of determining whether hyperfunctioning tissues have been completely excised. However, an intraoperative QPTH assay may fail to detect the presence of double parathyroid adenomas. Use of this assay in conjunction with preoperative and intraoperative localization studies has led to the advocacy of more directed cervical procedures, such as limited, video-assisted, and endoscopic parathyroidectomy.

Regenerative heat treatment of blades of high-temperature nickel alloys

An analysis of the operation of blades of gas turbine engines (GTE) manufactured from cast nickel alloys has made it possible to determine some of the causes of failure in operation, such as changes in the geometric dimensions or degradation of the microstructure. As a rule, the first cause is considered to be decisive. In order to increase the service life of blades partial regenerative repair of them is envisaged. In this case the dimensions of the blades are usually restored without allowing for possible changes in their structure, which can have a negative effect on operation after the restoration. For this reason, the second cause can become decisive in the reduction of their service life. This work is devoted to investigating the regularities of the degradation of the structure and properties of the material of cast GTE blades made of a high-temperature nickel alloy of the ZhS6U-VI type under operating conditions. A structural criterion determining the operating capacity of the olades and the ultimate level of structural degradation are established. A regenerative heat treatment to be conducted after partial exhaustion of the opet acing resource accompanied by structural changes that occur within the critical range of the structural criterion is suggested.

Complications of gastroesophageal antireflux surgery in neurologically impaired versus neurologically normal children

Antireflux surgery was performed in 234 children over a 5-year period; 153 were neurologically impaired (NI) and 81 were neurologically normal (NN). Initial presentation, demographic data, and type of antireflux operation were similar in the two groups. Eighty-six percent of the NI group versus 30% of the NN group had gastrostomy tubes placed. The incidence of late postoperative complications was 26% in the NI group and 12% in the NN group ( P < .01). During the late postoperative period, NI children underwent reoperation four times as frequently as NN children (19% v 5%, respectively; P < .01). Wrap herniation accounted for 38% of complications and 59% of reoperations in the late postoperative period. Mortality due to aspiration occurred in 9% of the NI group versus 1% of the NN group. Combined failure rate (reoperation plus aspiration-induced deaths) was 28% in NI and 6% in NN ( P < .01). We conclude that neurological status is the major predictor of operative success and that wrap herniation due to crural disruption is the most common cause of operative failure.

Primary vesicoureteric reflux treated by antireflux ureterocystostomy at the vertex of the bladder. A 12-year follow-up and analysis of operative failure.

A total of 618 children with primary vesicoureteric reflux (VUR) were examined preoperatively and 6, 9 and 24 months after an antireflux ureterocystostomy of the vertex of the bladder (AUVB); 206 children were operated on bilaterally, so that 824 AUVBs were performed. Most patients had grade 3 or 4 reflux and only 5% had grade 2 reflux. Successful results were noted in 792 ureteric units; in 10 cases of post-operative stenosis and 17 cases of recurrent VUR a second AUVB was performed. The following causes of operative failure were found: obstruction of the submucosal ureter after tailoring (5 cases), stricture of the new ureteric orifice (3), necrosis of the terminal part of the ureter (2), submucosal ureter too short or too wide (12) and fibrosis of the detrusor muscle over the submucosal ureter (5); a success rate of 84% was noted after the second procedure.

Determination of biological contaminants in fuels

The authors determine the characteristic indicators of outward appearance and composition of biomass artificially grown in water/ fuel systems under laboratory conditions. Two full pages of charts present their findings. They conclude that their methods give a reliable determination of the biological nature of contaminants in fuel and fuel systems, and can be used to reveal the causes of operational failures in equipment.

Dorsal rhizotomy for the relief of chronic pain.

✓ A retrospective study of 45 patients who had dorsal rhizotomies for relief of chronic pain is reported. The overall long-term success rate was 28% although initial results were much more favorable. The long-term results were correlated with a variety of preoperative and operative factors. Sex, age, history of narcotic use, compensation, number of roots cut, duration of pain, level of roots cut, effect of nerve blocks, or prior surgery for pain did not seem to influence the long-term results. The presence of arachnoiditis or pain subsequent to disc disease was associated with poorer results. Pain secondary to a malignancy responded better to this operation. The potential causes of operative failure are discussed.

The effects of fungi on the direct current surface conductance of electrical insulating materials.

The extent of visible fungus growth on pressuresensitive electrical insulating tapes, as well as the effects of fungi on the mechanical strength of the tapes, was reported previously (Berk and Teitell, 1951). seriously decreased the tensile strength of tapes with cellulosic backings but had no more than slight effects on the tensile strength of tapes with elastomeric backings. This report deals with the second phase of the investigation, the effects of fungi on the electrical properties of the pressure-sensitive insulating tapes and, particularly, the effects on surface conductance. The literature is somewhat controversial concerning the relative importance of moisture and fungus growth on the failure of electrical equipment in service (Leutritz and Hermann, 1946; Leutritz, 1948). The Summary Technical Report of the National Defense Research Council (1946) on Tropical Deterioration of Electric and Electronic Equipment states, Fungi are also important agents of deterioration in electric and electronic equipment. Hyphal strands of surfacegrowing fungi can introduce leakage paths which reduce insulation resistance and establish couples which promote electrolytic corrosion. Titus (1945) considered fungi to be secondary causes of operational failures but stated that fungus filaments, when bridging terminals, might cause flash-overs. Proskauer and Smith (1945) stated that microorganisms contribute to the retention of moisture on surfaces that would normally dry out quickly, and the presence of these microorganisms might produce paths of low electrical resistance. Leutritz and Hermann (1946) searched the literature from 1820, the year the galvanometer was invented, to 1945 and found no experiments that showed the effects of fungi on insulation resistance. They then studied the effects of humidity and fungus on unfilled and variously filled plastics and concluded that the decrease in insulation resistance was due to water absorption or adsorption and not due to fungi. There have been several additional investigations of the problem since 1945. Witt, Chapman, and Raskin (1952) tested various plastics exposed to fungus and humidity; they used nitrogen atmospheres to prevent fungus growth where only humidity was desired; and they reported that the presence of moisture overshadowed any effects that fungi might have produced. Luce and Mathes (1951) and Gauvey (1951) worked with plastic hook-up wire insulation and, using a technique of fumigation to prevent fungus growth, were able to separate the effects of humidity and fungi. They found that for many good plastic insulating materials there was a definite decrease in the direct current surface resistance caused by fungi and separate from any lowering caused by moisture. This decrease in resistance was detected electrically before any visual growth of fungi took place. Leonard and Patouillet (1951) reported on a laboratory method that compared creepage resistance results from sterilized and viable inocula, and they were able to show that viable fungi lowered the resistance. Dubois and Herou (1952) investigated the effects of mold on various plastic materials. They used as criteria the time required for travel of high voltage sparks and the number of drops of water or ammonium chloride solution required for a short circuit. They found that with some materials there is a degrading effect from the molds, which they attributed to the secretion of an electrolytic solution capable of penetrating the material. In studying a slightly different aspect of the problem, Blake, Kitchin, and Pratt (1950) and Blake and Kitchin (1949) reported that soil microorganisms can cause failure of rubber insulation. The decreases in volume resistance were so great that sensitive measuring methods were not necessary.

The Effects of Fungi on the Direct Current Conductance of Electrical Insulating Materials

The extent of visible fungus growth on pressuresensitive electrical insulating tapes, as well as the effects of fungi on the mechanical strength of the tapes, was reported previously (Berk and Teitell, 1951). Fungi seriously decreased the tensile strength of tapes with cellulosic backings but had no more than slight effects on the tensile strength of tapes with elastomeric backings. This report deals with the second phase of the investigation, the effects of fungi on the electrical properties of the pressure-sensitive insulating tapes and, particularly, the effects on surface conductance. The literature is somewhat controversial concerning the relative importance of moisture and fungus growth on the failure of electrical equipment in service (Leutritz and Hermann, 1946; Leutritz, 1948). The Summary Technical Report of the National Defense Research Council (1946) on "Tropical Deterioration of Electric and Electronic Equipment" states, "Fungi are also important agents of deterioration in electric and electronic equipment. Hyphal strands of surfacegrowing fungi can introduce leakage paths which reduce insulation resistance and establish couples which promote electrolytic corrosion." Titus (1945) considered fungi to be secondary causes of operational failures but stated that fungus filaments, when bridging terminals, might cause flash-overs. Proskauer and Smith (1945) stated that microorganisms contribute to the retention of moisture on surfaces that would normally dry out quickly, and the presence of these microorganisms might produce paths of low electrical resistance. Leutritz and Hermann (1946) searched the literature from 1820, the year the galvanometer was invented, to 1945 and found no experiments that showed the effects of fungi on insulation resistance. They then studied the effects of humidity and fungus on unfilled and variously filled plastics and concluded that the decrease in insulation resistance was due to water absorption or adsorption and not due to fungi. There have been several additional investigations of the problem since 1945. Witt, Chapman, and Raskin (1952) tested various plastics exposed to fungus and humidity; they used nitrogen atmospheres to prevent fungus growth where only humidity was desired; and they reported that the presence of moisture overshadowed any effects that fungi might have produced. Luce and Mathes (1951) and Gauvey (1951) worked with plastic hook-up wire insulation and, using a technique of fumigation to prevent fungus growth, were able to separate the effects of humidity and fungi. They found that for many good plastic insulating materials there was a definite decrease in the direct current surface resistance caused by fungi and separate from any lowering caused by moisture. This decrease in resistance was detected electrically before any visual growth of fungi took place. Leonard and Patouillet (1951) reported on a laboratory method that compared creepage resistance results from sterilized and viable inocula, and they were able to show that viable fungi lowered the resistance. Dubois and Herou (1952) investigated the effects of mold on various plastic materials. They used as criteria the time required for travel of high voltage sparks and the number of drops of water or ammonium chloride solution required for a short circuit. They found that with some materials there is a degrading effect from the molds, which they attributed to the secretion of an electrolytic solution capable of penetrating the material. In studying a slightly different aspect of the problem, Blake, Kitchin, and Pratt (1950) and Blake and Kitchin (1949) reported that soil microorganisms can cause failure of rubber insulation. The decreases in volume resistance were so great that sensitive measuring methods were not necessary.

GONIOSCOPY AND GLAUCOMA

Recent interest in gonioscopy is evident from the presentation of three papers and a lecture course on this subject during the 1940 meetings of the American Academy of Ophthalmology and Otolaryngology and the Pan-American Congress of Ophthalmology in Cleveland. Its value in clinical ophthalmology has been established by Troncoso, Thorburn, Werner, Vannas, Barkan and others. In the study of glaucoma it is valuable in several particular ways : first, in indicating the best location for surgical drainage in cases in which synechiae are present ; second, in determining the prognosis and ascertaining the causes of operative failure ; third, in indicating the type of secondary operation when reoperation is necessary ; fourth, in the differential diagnosis between primary glaucoma and certain types of secondary glaucoma ; fifth, in measuring the depth of the chamber angle (when gonioscopic observation is made with a microscope containing a micrometer eye piece), and last, but not least, in leading