Critical item

The failure mode of an equipment item describes the reason for the failure, and is often determined by analysing what causes historic failures in the particular item. This is another good reason for keeping records of the performance of equipment. For example, if it is recognised that a pump typically fails due to worn bearings after 8,000 hours in operation, a maintenance strategy may be adopted which replaces the bearings after 7,000 hours if that pump is a critical item. If a spare pump is available as a back-up, then the policy may be to allow the pump to run to failure, but keep a stock of spare parts to allow a quick repair. 

Breakdown and subsequent repair is clearly non-scheduled, but gives rise to nonavailability of the item. Some non-critical items may actually be maintained on a breakdown basis, as discussed in Section 11.3. Flowever, an item which is critical to keeping the production system operating will be designed and maintained to make the probability of breakdown very small, or may be backed up by a stand-by unit. 

In the past, commodity chemicals were generally priced on the basis of ROl. Capital cost was the most critical item, and those elements that ate related to capital cost were the principal factors in the selling price (excluding taw material cost in some cases). On this basis, a satisfactory ROl resulted in acceptable values for other criteria such as ROS or sales margin. Many analysts favor ROS as a benchmark for comparison because it is up to date and simple and because it is increasingly difficult to determine a tme ROl based on what profits might be on plants built under indation and expensive capital and constmction costs. 

Actual progress made with construction work can be indicated on the bar chart by filhng in the open bars according to the percentage toward completion. Comparison of the actual progress bar for the whole project with the cumulative labor-hour curve indicates whether the job is ahead of schedule or not. If corrective action is required, effort should be concentrated on the key or critical items. 

The critical items may then be checked for the required response spectra (RRS) as discussed above. 

Evaluate the current operability of critical items for the conditiorinc drums... 

HEPA filters consist of a filter pack sealed into a case. The filter pack or core is made by pleating a continuous web of fiberglass paper back and forth over corrugated separators. The filter pack is sealed into a full-depth wood or steel casing using a elastomeric sealant. Gasketing is a critical item to ensure that the filter passes the air leakage tests. 

One technique you can use to identify the new controls is to establish a list of critical items or areas by analyzing the design. Such items may include ... 

The lists of critical items that were described under Identifying controls in Part 2 Chapter 2, together with Failure Modes and Effects Analysis and Hazard Analysis, are techniques that aid the identification of characteristics crucial to the safe and proper functioning of the product. 

Preparation of a field checklist to inspect critical items prior to start-up... 

Because steam is usually a critical item in a chemical plant, it is not advisable to rely on only one boiler. This means that boiler size is not a factor. Only enough generating capacity should be installed to meet the needs of the initial plant, and additional boilers should be installed to meet expansion needs. Cooling towers should also be designed to handle only the initial requirements.39... 

Critical currents, 23 821-823 in superconducting, 23 819-825 Critical event (CE), 15 462 Critical failure, 26 982 Critical features, in separating nonideal liquid mixtures, 22 307 Critical fields, thermodynamic, 23 809-811 Critical flocculation concentration, 11 631 Critical item evaluation, for reliability, 26 991... 

The next item in the loop is a decision point for possibly introducing the use of inductive reasoning methods into the deliberations. If the deductive process continues to indicate progress, then additional facts are procured or the logic tree is restructured. For example, one witness stated a particular valve was open, yet the post-incident inspection found it to be closed. The team must be careful to ensure that the valve is closed because of the actions taken prior to the incident, and not as a result of post-event response activities. The position of this particular valve may be a critical item in determining which of two scenarios is the more probable case. The incident investigation team would then initiate a short-term action item to conduct a mini-investigation to resolve this question. 

Defense Logistics Actions Needed to Improve the Availability of Critical Items during Current and Future Operations, Report GAO-05-0275, United States Government Accountability Office, April 2005, p. 19 ff. 

All critical items should be calibrated every 6 months. Noncritical items should be calibrated every 12 months. If necessary, recalibration frequency should be reviewed and revised. 

The pharmaceutical manufacturer is not normally represented at supplier factory calibrations but for critical items should consider an option to inspect instrumentation and witness tests. Calibration certificates referencing the test procedure and test equipment should be sought, particularly for the instruments and regulating devices directly associated with quality-related critical parameter measurements and control. 

Table 6 Critical Items for Inclusion in a Qualification Protocol... 

Standard operating procedures (SOPs) are required for all routine activities that are critical to the successful outcome of the study including quality assurance procedures and inspections. Most of the SOPs for the field activities are written by the field scientists with guidance from the Quality Assurance Section. For the field activities, it is required that at each site there be SOPs for such things as how field plots are established and the plot boundaries marked, the maintenance of sample freezers, how to calibrate and maintain chemical balances and chemical application equipment, and how to obtain test chemicals. If an SOP for a critical item of equipment is not available, the study would be considered to be not in compliance with the principles of the GLP guidelines. The distribution of SOPs is carefully controlled so that when an SOP is changed, all outdated copies can be exchanged for the new version. 

Backups of firmware or software are critical items for operational continuity. 

In many instances, the reason is very simple transport and dirt It is extremely important that both the transport and storage of these critical items are given due attention. 

The complex internal set-up of a typical rotary valve is shown in Figure 3.82 [38], The complexity of a rotary valve causes a number of problems, of which cross-talk is the most critical item. Nevertheless, a rotary valve is certainly the easiest to realize type of valve if a large number of individual gas streams have to be switched. Especially the transformation of the array-type arrangement in the reaction section to a rotary arrangement in the valve is a critical item. Here, a micro structured plate was applied to allow such a transformation. As an alternative, the individual... 

Serial numbers shall be added to the above table when the item is used. For critical items the serial numbers shall be recorded on the process record where indicated at the point of use. 

CRITICAL ASSESSMENT OF THE METHOD A very critical item has been a tendency of ACTH to fluctuate widely and rapidly under conditions of stress (Meeran 1989, Lambert 1985, Goverde 1989). This is especially a problem in studies with dogs, where the experiments need to be performed under stress-free conditions and even then there will be the difficulty of rapidly fluctuating concentrations. 

Technical background of critical items in the biodiesel standard 86... 

TECHNICAL BACKGROUND OF CRITICAL ITEMS IN THE BIODIESEL STANDARD... 

Product performance qualification to verify that critical items/records are consistent (e.g., batch records, labeling variants)... 

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