Revision control

To increase the production rate, the flowrates of both FB0 and F are increased in Figure 3.44. This revised control structure provides stable base-level regulatory control for this system with a very temperature-sensitive specific reaction rate. 

The firm has failed to establish an overall revision control system for the program thronghont its software life cycle. [FDA 483, 2001]... 

There were no written Standard Operating Procedures for hardware and software change control and software revision control. [FDA 2001]... 

There were no written user standard operating procedures. .. [for] system validation, hardware and software change control, revalidation, user operations, security guidelines, software revision control, virus detection, disaster recovery, and backup and audit trail archival. [FDA 483, 1999]... 

Revision Control A process of tagging and storing various development stages of an application with the ability to backtrack to earlier versions. 

Change control Who initiates changes Who authorizes changes Are there procedures for change control Do they include impact analysis, test plans Is there a formal revision control procedure Will all updates get new version numbers Are there procedures for user documentation updates How are customers informed on changes ... 

To establish and when necessary revise control procedures and specifications. 

A particular tool for version control will be outlined later (the RCS, Revision Control System), for the moment we take the opportunity to introduce the conditional compilation facility of a macro processor which is typical of Unix-based systems. 

Just as in the case of the Revision Control System for version control, there is a public domain system available which is the best that there is the WEB system of program development. 

The Revision Control System (RCS) is a set of tools which enables the recovery of any previous version of a changing document from a single file which contains the initial version and all the changes to which it has been subject in its development history since its introduction to the RCS system. 

These are the codes for Version 1 of the SCF program, one or other of them should now be entered into the Revision Control System (RCS) described in Chapter 11 and Appendix 11.A. 

Completely independent safety monitors to prevent common flaws. This includes signal sources, different component models and different program types Hardwired safety circuit and critical devices such as track limits and slack rope Strict software revision control... 

As mentioned earlier, automated tests are an integral part of development of the systems. They come in the range from unit tests of a single function to whole-system tests. These tests are mn before any piece of code is checked into the revision control system. A continuous integration [72] server can also be set up, that continuously checks out code from the revision control system and runs aU the tests to detect errors at the system level. If a bug is found, regression tests that expose the bug are written before the bug is corrected. The regression test is then included in the test suite that are run at regular intervals, to detect if the bug reappears. 

A document control system, including standard practices for numbering documents, their filing, the system of document approval and authorization of issue, distribution control, revision control, and archiving. 

The SIS functionality should be documented in a design basis that is maintained under revision control as process safety information for the life of the system. The SIS design basis should address the following ... 

Update documents to as-built status, incorporating changes made since the last formal drawing/document revision. Maintain documentation under revision control for the life of the equipment. Documentation should be traceable to the process hazard analysis and should be auditable. 

The two control charts can be compared by analyzing the operating characteristics curves (OC curves) and ARL curves. The OC curve plots the probability of not detecting the shift with respect to file shift of the mean. In Fig. 4, the OC curve of 3ff control chart shows better result, i.e., lower probability of not detecting the shift, than that of the revised control chart using correction factor if the shifted mean is more than 30 % of the original value. However, it should be noted that the cases when the shifted mean is less than the in-control mean are the main focus of the monitoring process. Taken this into consideration, it can be seen that the revised control chart performs better. 

Also, Fig. 5 shows that the OC curve of the revised control chart has maximum value of ARL at the in-control mean value, while the OC curve of the 3[Pg.513]

Revised Control Limits Using Cornish-Fisher Expansion (Using Skewness Only)... 

Noted that by the use of Weibull transformation with correction factor, the control limits of the revised control chart are... 

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