Task chart

This study describes one stage of a soft tool realisation, which facilitate and improve the task of the expert for x-ray image interpretation and decision-making. We are interested by tbe first four stages of this flow chart. 

This task can be avoided if a hydrocarbon stream is the limiting resistance by the use of the caloric temperature charts developed by Colburn [Ind. Eng. Chem., 25, 873 (1933)]. 

The size of the project team depends on the particular tasks that are to be performed and the hazards that may be encountered. Keep in mind that a wide variety of disciplines may not be required for every project. During the early stages of planning, an organizational chart should be developed. This chart can serve to visually depict the following ... 

A plan is more than a list of goals, a bar chart, or a schedule of activities. For the business plan to be effective it needs to define how the measures it covers are to be achieved and the resources to achieve them obtained. There may well be supplementary plans for this purpose. The plan or plans also need to define who is to be responsible for achieving the goals and implementing the plans. Once this is done and the provisions communicated to those affected, a method of tracking achievement can be put in place. To track performance effectively the implementation of the plan needs to be phased such that target dates are set for the determination and acquisition of resources, the issue of detail implementation plans, the organization of work, and the completion of individual tasks. 

For these tasks identify likely internal and external error modes using flow charts and methods described in Chapter 6. 

For tasks that rely on decision-making rather than on fine manipulations, the activity chart can assume a columnar format, with columns recording process information attended and subsequent changes of discrete control settings. 

Although little training is required to learn the technique, decision/action charts should be verified by different operators to ensure that a representative view of the decision task is obtained. The advantages and disadvantages of the technique are summarized as follows ... 

Decision/action charts can be used to represent tasks that involve decision-making, time-sharing, or complex conditions and contingencies. 

Decision/action charts are linear descriptions of the task and provide no information on the hierarchy of goals and objectives that the worker is trying to achieve. 

Operational sequence diagrams are flcw-charting techniques that represent any sequence of control movements and information collection activities that are executed in order to perform a task. Various activities in the diagram are represented with a symbolic notation, supported where necessary by a text description. For the majority of simple applications, OSDs assume a linear flow drawn from top to bottom with a limited degree of branching and looping. The symbols used are usually tailored to fit the type of task being studied and its level of analysis. 

These diagrams focus on the temporal or time relationships of operations and they can be used to solve resource allocation problems, to determine whether there is any potential for time stress, and to consider alternative work methods in the execution of a procedure. An example drawn from traditional industrial engineering methods is shown in Figure 4.7. The chart is used to analyze the interaction between people and equipment. As indicated in the summary portion of this chart, there is a high proportion of idle time which would probably indicate the use of alternative procedures in the execution of this task. The chart enables the analyst to see the relationships among the activities of the different components in planning such alternatives. 

The whole range of error types that could occur at each task step are described in Figure 4.16. The terms action errors and checking errors are self-explanatory. Retrieval errors refer to the retrieval of infonnation either from an external source (e.g., a chart recorder or a procedure) or from memory. Transmission/ communication errors refer to communications among individuals either directly or via written communications. Selection/choice errors refer to making incorrect choices among alternative operations, for example, manual instead of automatic. 

Based on the collected information, a decision/action (DA) chart was developed to provide an overview of the main decisions involved in the blowdown operation and the main influential factors such as time stress, conflicting responsibilities, risk of gas ignition etc. Task Analysis and Error Analysis of the blowdown operation were subsequently carried out to obtain a description of the sequence of tasks steps and the likely human error modes which could occur. 

Two new sections on the protection of phosphates and the alkyne-CH are included. All other sections of the book have been expanded, some more than others. The section on the protection of alcohols has increased substantially, reflecting the trend of the nineties to synthesize acetate- and propionate-derived natural products. An effort was made to include many more enzymatic methods of protection and deprotection. Most of these are associated with the protection of alcohols as esters and the protection of carboxylic acids. Here we have not attempted to be exhaustive, but hopefully, a sufficient number of cases are provided that illustrate the true power of this technology, so that the reader will examine some of the excellent monographs and review articles cited in the references. The Reactivity Charts in Chapter 10 are identical to those in the first edition. The chart number appears beside the name of each protective group when it is first introduced. No attempt was made to update these Charts, not only because of the sheer magnitude of the task, but because it is nearly impossible in... 

Simple production of bar charts or Gantt charts detailing the task time scales ... 

With time duration determined for each task of the project, the next step is to determine the earliest and latest starting times for each task. There are two commonly used methods for charting the project Gantt charts and PERT diagrams. The details of these two methods are discussed on the following pages. 

Another helpful tool is a project control chart, which uses budget and schedule plans in a quick status report of the project. It compares actual to plan, calculates a variance on each task completed, and tallies a cumulative variance for the project. 

To prepare a project control chart, refer to the work breakdown structure and list all of the tasks of the project. Then, use the schedule to list the time planned to complete each task, and use the budget to list the expected cost of each task. 

As each project task is completed, record the actual time and actual cost. Calculate variances and carry the cumulative total forward. This technique can easily be put into a spreadsheet format on your personal computer. Some large projects may be able to create this format for a report that uses cost and schedule data that is routinely captured by the company s computerized accounting system. Figure 51.10 illustrates a typical project control chart. 

Algorithm Also known as a flow chart. It is an abstract description of a procedure or a program. A specified, step-by-step procedure for performing a task that will lead to a correct answer or solving a problem. 

Figure 9.12 Gantt chart for the tasks outlined in Figure9.11.

Additional research on the prediction of flow patterns is a necessity, for until detailed stability criteria are developed for the transition from one flow pattern to another, there is no alternative to the empirical flow pattern charts. Some progress in theoretically defining the transition from stratified to wavy or slug flow has been made by Russell and Etchells (R3). Inaccuracy and uncertainty in flow pattern prediction makes estimation of the in situ hydrodynamic quantities and the rate of heat transfer a difficult task. 

As Levenspiel points out, the optimum size ratio is generally dependent on the form of the reaction rate expression and on the conversion task specified. For first-order kinetics (either irreversible or reversible with first-order kinetics in both directions) equal-sized reactors should be used. For orders above unity the smaller reactor should precede the larger for orders between zero and unity the larger reactor should precede the smaller. Szepe and Levenspiel (14) have presented charts showing the optimum size ratio for a cascade of two reactors as a function of the conversion level for various reaction orders. Their results indicate that the minimum in the total volume requirement is an extremely shallow one. For example, for a simple... 

The Farinograph-E (Figure 6) uses a PC to process the data from the Farinograph this is a considerable improvement over measuring pieces of paper from a chart recorder. The software supplied runs under Windows and can multi-task so that one PC can handle data from several instruments. This is particularly convenient as the Farinograph is used to prepare doughs for the Extensograph. 

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