how to write a good produit specification

source:http://www.microtoolsinc.com/Howsrs.php

What are the benefits of a Great SRS?

The IEEE 830 standard defines the benefits of a good SRS(Software Requirements Specification):

Establish the basis for agreement between the customers and the suppliers on what the software product is to do. The complete description of the functions to be performed by the software specified in the SRS will assist the potential users to determine if the software specified meets their needs or how the software must be modified to meet their needs. [NOTE: We use it as the basis of our contract with our clients all the time].

Reduce the development effort. The preparation of the SRS forces the various concerned groups in the customer抯 organization to consider rigorously all of the requirements before design begins and reduces later redesign, recoding, and retesting. Careful review of the requirements in the SRS can reveal omissions, misunderstandings, and inconsistencies early in the development cycle when these problems are easier to correct.

Provide a basis for estimating costs and schedules. The description of the product to be developed as given in the SRS is a realistic basis for estimating project costs and can be used to obtain approval for bids or price estimates. [NOTE: Again, we use the SRS as the basis for our fixed price estimates]

Provide a baseline for validation and verification. Organizations can develop their validation and Verification plans much more productively from a good SRS. As a part of the development contract, the SRS provides a baseline against which compliance can be measured. [NOTE: We use the SRS to create the Test Plan].

Facilitate transfer.The SRS makes it easier to transfer the software product to new users or new machines. Customers thus find it easier to transfer the software to other parts of their organization, and suppliers find it easier to transfer it to new customers.

Serve as a basis for enhancement. Because the SRS discusses the product but not the project that developed it, the SRS serves as a basis for later enhancement of the finished product. The SRS may need to be altered, but it does provide a foundation for continued production evaluation. [NOTE: This is often a major pitfall ?when the SRS is not continually updated with changes]

BIOS报警声意义

BIOS报警声意义


Award BIOS
　　1短：系统正常启动。恭喜，你的机器没有任何问题。
　　2短：常规错误，请进入CMOS Setup，重新设置不正确的选项。
　　1长1短：内存或主板出错。换一条内存试试，若还是不行，只好更换 主板。
　　1长2短：显示器或显示卡错误。
　　1长3短：键盘控制器错误。检查主板。
　　1长9短：主板 Flash RAM或EPROM错误，BIOS损坏。换块Flash RAM试 试。
　　不断地响（长声）：内存条未插紧或损坏。重插内存条，若还是不行， 只有更换一条内存。
　　不停地响：电源、显示器未和显示卡连接好。检查一下所有的插头。
　　重复短响：电源有问题。
　　无声音无显示：电源有问题。

AMI BIOS
　　1短：内存刷新失败。更换内存条。
　　2短：内存ECC较验错误。在 CMOS Setup中将内存关于ECC校验的选项 设为Disabled就可以解决，不过最根本的解决办法还是更换一条内存。
　　3短：系统基本内存（第1个64kB）检查失败。换内存。
　　4短：系统时钟出错。
　　5短：中央处理器（CPU）错误。
　　6短：键盘控制器错误。
　　7短：系统实模式错误，不能切换到保护模式。
　　8短：显示内存错误。显示内存有问题，更换显卡试试。
　　9短：ROM BIOS检验和错误。
　　1长3短：内存错误。内存损坏，更换即可。
　　1长8短：显示测试错误。显示器数据线没插好或显示卡没插牢


POENIX的BIOS报警声（以前的老板上有许多POENIX的）

1短 系统启动正常
1短1短1短 系统加电初始化失败
1短1短2短 主板错误
1短1短3短 CMOS或电池失效
1短1短4短 ROM BIOS校验错误
1短2短1短 系统时钟错误
1短2短2短 DMA初始化失败
1短2短3短 DMA页寄存器错误
1短3短1短 RAM刷新错误
1短3短2短 基本内存错误
1短3短3短 基本内存错误
1短4短1短 基本内存地址线错误
1短4短2短 基本内存校验错误
1短4短3短 EISA时序器错误
1短4短4短 EISA NMI口错误
2短1短1短 前64K基本内存错误
3短1短1短 DMA寄存器错误
3短1短2短 主DMA寄存器错误
3短1短3短 主中断处理寄存器错误
3短1短4短 从中断处理寄存器错误
3短2短4短 键盘控制器错误
3短1短3短 主中断处理寄存器错误
3短4短2短 显示错误
3短4短3短 时钟错误
4短2短2短 关机错误
4短2短3短 A20门错误
4短2短4短 保护模式中断错误
4短3短1短 内存错误
4短3短3短 时钟2错误
4短3短4短 时钟错误
4短4短1短 串行口错误
4短4短2短 并行口错误
4短4短3短 数字协处理器错误
BIOS自检与开机故障相关问题