【正文】 ............................................................................................... 13 、假定和限制 ................................................................................................. 14 .......................................................................................... 14 ............................................................................................................... 14 3對現(xiàn)有系統(tǒng)的分析 ....................................................................................................... 14 ............................................................................................. 15 ............................................................................................................... 15 ............................................................................................................... 15 ...................................................................................................................... 15 ...................................................................................................................... 15 .................................................................................................................. 15 4所建議的系統(tǒng) .............................................................................................................. 15 ............................................................................................. 16 ............................................................................................. 16 ............................................................................................................... 16 ...................................................................................................................... 16 .................................................................................................. 16 .................................................................................................. 16 .................................................................................... 16 .................................................................................... 17 .................................................................................................. 17 ....................................................................................... 17 ........................................................................................... 17 .................................................................................................................. 17 .......................................................................................... 18 5可選擇的其他系統(tǒng)方案 ................................................................................................ 18 1 .............................................................................................. 18 2 .............................................................................................. 18 6投資及效益分析 .......................................................................................................... 18 ...................................................................................................................... 18 .................................................................................................. 19 .............................................................................................. 19 .................................................................................................. 19 11 ...................................................................................................................... 20 ..................................................................................................... 20 .....................................................................