Large projects

The cost of off-sites ranges typically from 20 to 40 percent of the total installed cost of the plant. In general terms, the larger the plant, the larger will be the fraction of the total project cost which goes to off-sites. In other words, a small project will require typically 20 percent of the total installed cost as off-sites. For a large project, the figure will be typically up to 40 percent. 

A technique widely used by the industry is Critical Path Analysis (CPA or Network Analysis ) which is a method for systematically analysing the schedule of large projects, so that activities within a project can be phased logically, and dependencies identified. All activities are given a duration and the longest route through the network is known as the critical path. 

Then, establish the same concept for all other unit or block processing systems. This is often helpful for large projects, such as refinery or grass roots chemical processes. 

In some cases, they may be anticipated by a knowledge of the status of the process data prior to the start of engineering acthity. The larger projects are somewhat easier to group than the smaller ones. Process engineering is not always handled as completely for the small jobs. This is to say that flowsheets may be simplified, detailed equipment and line schedules may not be required, and the over-all project can be completely visualized at the outset, which is not the case with large projects. 

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. 

Large and complex projects will be monitored as the expenditure proceeds while smaller outlays will be looked at after completion. The purpose of such monitoring is to provide a comparison of actual expenditure with that estimated when the project was sanctioned. The accounting or internal audit departments will normally carry this out. However, for a sensible comparison to be achieved it is essential that the planned expenditure demonstrated in the project be classified in the same way that the actual expenditure will be analyzed. While somewhat obvious, this is an area where very great difficulty is often met in practice, especially where large projects are involved. 

The general arrangement of the apparatus is shown in Fig. 12.26. In recent years both the powder and wire processes have been automated for large projects. Mechanisation allows the use of large nozzles of special contours and the replacement of pneumatic drives by electric motors. Controls are usually from consoles by pneumatic or electronic signal systems. 

If the surface over which the fluid is flowing contains a series of relatively large projections, turbulence may arise at a very low Reynolds number. Under these conditions, the frictional force will be increased but so will the coefficients for heat transfer and mass transfer, and therefore turbulence is often purposely induced by this method. 

The second perspective might be that of the leader of some large project where chemical analyses are just a side issue, where sample numbers are large and chemical niceties might be completely swamped by, say, biological variability here a statistician will be necessary to make sense of the results in the context of a very complex model. Chemistry is a bit harder to relate to than many other industries in that the measured quantities are often abstract, invisible, and only indirectly linked to what one wants to control. 

The detailed design and specification of the automatic control schemes for a large project is usually done by specialists. The basic theory underlying the design and specification of automatic control systems is covered in several texts Coughanowr (1991), Shinskey (1984) (1996) and Perry et al. (1997). The books by Murrill (1988) and Shinskey (1996) cover many of the more practical aspects of process control system design, and are recommended. 

Example 2.1 A new heat exchanger is to be installed as part of a large project. Preliminary sizing of the heat exchanger has estimated its heat transfer area to be 500 m2. Its material of construction is low-grade stainless steel, and its pressure rating is 5 bar. Estimate the contribution of the heat exchanger to the total cost of the project (CE Index of Equipment = 441.9). 

If a company plans to finance a large project by issuing new stock, it means that the percentage of the company s ownership represented by one share of stock decreases. As a result, the stock price often goes down after a large new block of stocks is issued. Because of this, when a large new block of stock is issued these stocks must be sold at a price below that currently listed on the stock exchange. 

He must update the schedules at least monthly. This means obtaining a new CPM diagram based on current knowledge. He wants the results as soon as possible after the raw data have been collected, so he can make decisions while the information is current. Doing the calculations by hand would take too long for any large project. 

NPV takes into account the size and profitability of a project, but the IRR measures only profitability. If a company has sufficient resources to consider several small projects, given a prespecified amount of investment, a number of high-value IRRs usually provide a higher overall NPV than a single large project. 

A small project may need only one of these views. The domain view can map directly into classes, which also constitutes the units of work without any higher-level component structuring and the domain view can run in a single process on a single machine. A large project can use all these views and can even introduce new ones. These views are not independent and it is critical to know how they relate to each other. 

Quality Assurance and Quality Control of Large Projects... 

This case study was carried out in the Research and Teaching Faboratory of Applied Botany under the auspices of the Department of Biology of the University of Joensuu, Finland (N 62° 36 E 29° 40 ) from 1999 to 2003 as a part of the larger project, Quinolizidine alkaloids in arctic and sub-arctic flora . This large project explores the broader problem of QAs occurring in... 

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