【正文】 these data elements e from? Since they are output by Generate reorder, they must either be Input to or generated by this process. Data flow into Generate reorder for STOCK。s basic functions, the analyst39。s environment? it be solved at a reasonable cost? If the answer to any one of these questions is no, the system should not be developed. Given a good problem definition and a positive feasibility study, the 3 analyst can turn to planning and developing a problem solution. 2 2 Analysis As analysis begins, the analyst understands the problem. The next step is determining what must be done to solve it. The user knows what must be done 1 during analysis。 definition 2 At the end of each step, results are documented and shared with both the user and the programmers. The idea is to catch and correct errors and misunderstandings as early as possible. Perhaps the best way to illustrate the process is through example. Picture a small clothing store that purchases merchandise at wholesale, displays this stock, and sells it to customers at retail. On the one hand, too much stock represents an unnecessary expense. On the other hand, a poor selection discourages shoppers. Ideally, a balance can be achieved: enough, but not too much. Complicating matters is the fact that inventory is constantly changing, with customer purchases depleting stock, and returns and reorders adding to it. [1] The owner would like to track inventory levels and reorder and given item just before the store runs out. For a single item, the task is easyjust count the stockonhand. Unfortunately, the store has hundreds of different items, and keeping track of each one is impractical. Perhaps a puter might help. 21 Problem Definition The first step in the systems analysis and design process is problem definition. The analyst39。I 附錄 1 外文翻譯 (原文 ) Systems Analysis and Design Working under control of a stored program, a puter processes data into information. Think about that definition for a minute. Any given puter application involves at least three ponents: hardware, software, and data. Merely writing a program isn39。s field. To plicate matters, users and programmers often seem to speak different languages, leading to munication problems. A systems analyst is a professional who translates user needs into technical terms, thus serving as a bridge between users and technical professionals. Like an engineer or an architect, a systems analyst solves problems by bining solid technical skills with insight, imagination, and a touch of art. Generally, the analyst follows a welldefined, methodical process that includes at least the following steps。s understanding of the problem is essential. The user should review and correct this written statement. The time to catch misunderstandings and oversights is now, before time, money and effort are wasted. Often, following a preliminary problem definition, the analyst performs a feasibility study. The study a brief capsule version of the entire systems analysis and design process, attempts to answer three questions: the problem be solved? it be salved in the user39。s owner wants to selectively look at the inventory level for any product in short supply and, if appropriate, order replacement stock, so the system must be able to municate with management. Finally, following management authorization, the system should generate a reorder ready to send to a supplier. Fig 1 Given the system39。s memory. 4 Finally, data flow between sources, destinations, processes, end data stores over data flows, which are represented by arrows. Fig 2 Figure 2 shows a preliminary data flow diagram for the inventory system. Start with CUSTOMER. Transactions flow from a customer f into the system, where they are handled by Process transaction. A data store, STOCK, holds data on each item in inventory. Process transaction changes the data to reflect the new transaction. Meanwhile, MANAGEMENT accesses the system through Communicate, evaluating the data in STOCK and, if necessary, requesting a reorder. Once, a reorder is authorized. Generate re