项目管理专业英语课件.ppt

typical functions include defining/describing classifying / categorising giving examples comparing and contrasting: similarities and differences expressing reasons and explanations / cause and effect the thermostat controls the temperature. the thermostat is used for controlling the temperature. the function of the thermostat is to control the temperature. the thermostat serves to (helps to) control the temperature. a thermostat is an instrument for controlling the temperature. a thermostat enables the researcher to measure the temperature accurately. tables and diagrams the writer does not simply add the visual presentation to the text, but includes some sort of comment. typically the writer will include (swales nonmetals usually are not. most metals are malleable; they can be hammered into flat sheets; nonmetals lack this quality. some metals are also ductile; they can be drawn out into thin wires; nonmetals are not usually ductile. metals usually have luster, and are able to reflect light. they also have a high density. nonmetals usually do not exhibit these properties. a few elements, such as arsenic and antimony, exhibit both metallic and nonmetallic properties and are sometimes referred to as metalloids. fig. 1 “waterfall” or sequential development method vs. iterative development method one of the most important reasons for the huge success of concurrent engineering is that by definition it redefines the basic design process structure that was based on a sequential design flow, sometimes called the waterfall model. concurrent engineering significantly modifies this outdated method and instead opts to use what has been termed an iterative or integrated development method. the two design processes can be seen graphically in figure 1. the waterfall method moves in a completely linear fashion by starting with user requirements and sequentially moving forward to design, implementation and additional steps until you have a finished product. the problem here is that the design system does not look backwards or forwards from the step it is on to fix possible problems. in the case that something does go wrong, the design usually must be scrapped or heavily altered. on the other hand, the iterative design process is more cyclic in that, as mentioned before, all aspects of the life cycle of the product are taken into account, allowing for a more evolutionary approach to design. transitional signals transitional words are cohesive ties to connect the sentences and paragraphs so that a piece of writing moves naturally and logically. 1. time/order at first, eventually, finally, first, firstly, in the end, in the first place, in the second place, lastly, later, next, second, secondly, to begin with 2. comparison/similar ideas in comparison, in the same way, similarly, in contrast with 3. contrast/opposite ideas but, despite, in spite of, even so, however, in contrast, in spite of this, nevertheless, on the contrary, on the other hand, still, whereas, yet, in contrast to 4. cause and effect accordingly, as a consequence, as a result, because, because of this, consequently, for this reason, hence, in consequence, in order to, owing to this, since, so, so that, therefore, thus, for all the above reasons 5. examples for example, for instance, such as, thus, as follows 6 generalization as a rule, generally, in general, normally, on the whole, in most cases, usually 7. stating the obviousness after all, as one might expect, clearly, it goes without saying, naturally, obviously, of course, surely, in fact 8. attitude admittedly, certainly, fortunately, luckily, oddly enough, strangely enough, undoubtedly, unfortunately 9. summary/conclusion finally, in brief, in conclusion, in short, overall, so, then, to conclude, to sum up, in a nutshell 10. explanation/equivalence in other words, namely, or rather, that is to say, this means, to be more precise, to put it another way, specifically, to be more specific 11. addition apart from this, as well as, besides, furthermore, in addition, moreover, nor, not only.but also, too, what is more 12. condition in that case, then, given 13. support actually, as a matter of fact, in fact, indeed 14. contradiction actually, as a matter of fact, in fact 15. emphasis chiefly, especially, in detail, in particular, mainly, notably, particularly paragraphs for many years, project managers have relied on experience and the prevailing industry norms as a basis to develop cost estimate. however, basing estimates on expert judgment is problematic: this approach is not repeatable and the means of deriving an estimate are not explicit. it is difficult to find highly experienced estimators for every new project. the relationship between cost and system size is not linear. cost tends to increase exponentially with size. the expert judgment method is appropriate only when the sizes of the current project and past projects are similar. budget manipulations by management aimed at avoiding overrun make experience and data from previous projects questionable. software cost estimation historically has been a major difficulty in software development. several reasons for the difficulty have been identified: lack of a historical database of cost measurement software development involving many interrelated factors, which affect development effort and productivity, and whose relationships are not well understood lack of trained estimators and estimators with the necessary expertise little penalty is often associated with a poor estimate a gantt chart is a type of bar chart that illustrates a project schedule. gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project. terminal elements and summary elements comprise the work breakdown structure of the project. some gantt charts also show the dependency (i.e. precedence network) relationships between activities. gantt charts can be used to show current schedule status using percent-complete shadings and a vertical “today“ line as shown here. although now regarded as a common charting technique, gantt charts were considered revolutionary when they were introduced. in recognition of henry gantts contributions, the henry laurence gantt medal is awarded for distinguished achievement in management and in community service. this chart is used also in information technology to represent data that has been collected. gantt charts have become a common technique for representing the phases and activities of a project work breakdown structure (wbs), so they can be understood by a wide audience. although a gantt chart is useful and valuable for small projects that fit on a single sheet or screen, it may become quite unwieldy for projects with more than about 30 activities. larger gantt charts may not be suitable for most computer displays. a related criticism is that gantt charts communicate relatively little information per unit area of display. that is, projects are often considerably more complex than can be communicated effectively with a gantt chart. although project management software can show schedule dependencies as lines between activities, displaying a large number of dependencies may result in a cluttered or unreadable chart. gantt charts only represent part of the triple constraints (cost, time and scope) of projects, because they focus primarily on schedule management. moreover, gantt charts do not represent the size of a project or the relative size of work elements, therefore the magnitude of a behind-schedule condition is easily misconcepted. if two projects are the same number of days behind schedule, the larger project has a larger impact on resource utilization, yet the gantt does not represent this difference. the method of constructing the network is important for the application of other complex planning technologies such as pert and cpm. project networks project networks consists of a number of nodes and a number of arcs. there are two alternatives for presenting project networks. activity-on-arc (aoa): each activity is presented as an arc. a node is used to separate an activity from each of its immediate predecessors. activity-on-node (aon): each activity is represented by a node. the arcs are used to show the precedence relationships. aon vs. aoa aon are considerably easier to construct than aoa. aon are easier to understand than aoa for inexperienced users. aon are easier to revise than aoa when there are changes in the network. the critical path method (cpm) or critical path analysis, is a mathematically based algorithm for scheduling a set of project activities. it is an important tool for effective project management. the program (or project) evaluation and review technique, commonly abbreviated as pert, is a model for project management designed to analyze and represent the tasks involved in completing a given project. it is commonly used in conjunction with the critical path method or cpm. pert was developed primarily to simplify the planning and scheduling of large and complex projects. it was developed in 1957 to support the u.s. navys polaris nuclear submarine project. it was able to incorporate uncertainty by making it possible to schedule a project while not knowing precisely the details and durations of all the activities. it is more of an event-oriented technique rather than start- and completion- oriented, and is used more in projects where time, rather than cost, is the major factor. this project model was the first of its kind, a revival for scientific management, founded by frederick taylor and later refined by henry ford. dupont corporatio