2.1 What is SPI?

SPI is the act of creating a new and improved software process in order to obtain a benefit. In other words, SPI is used to create a new and improved software process to achieve some level of benefits. The benefits are often increased revenues or profits, decreased costs, and significant cost savings. It is somewhat ironic that the field of SPI has evolved to include cost savings. Early attempts at SPI were designed to improve quality and reliability at any cost.

SPI is simply the act of changing the software development and maintenance process. The goals are usually to increase efficiency, decrease costs, and increase profitability. For instance, SPI can be used to create a new and improved process for software project management.

This may result in faster cycle times, shorter time to market, higher customer satisfaction, and alignment with strategic goals. Improved project management also leads to accurate time and budget accounting and better cost and schedule performance. Lower defect rates, smaller module sizes, increased verification and validation efficiency, and increased productivity also result. Improvement certainly leads to better cost, quality, and reliability estimation and higher software quality and reliability.

SPI is used to create a new and improved software process. First, the performance of an old software process is measured using statistical process control. Then, a new and simplified software process is formed to improve performance. Oftentimes, the new and improved software process is piloted to measure its new performance. Finally, the new software process which exhibits the desired performance level may be institutionalized.

SPI is used to create new software processes for strategic software activities. Software project management and software quality management are certainly strategic activities. However, software design management is a very strategic software activity.

SPI of processes for software quality management is a proven discipline which yields orders-of-magnitude improvement. SPI of processes for software project management is starting to achieve international recognition. It is fueled by emerging data and hard economic justification for this discipline. SPI of processes for software design management is a fledgling discipline. Its economic underpinnings are anchored in the fields of software reuse and product line management.