SSPF Evaluation

Cost

The table above shows the cost of developing the two versions of SSPF.   At first glance, the effort saved may not seem significant. However, a more detailed analysis gives a better picture.

• The costs include not just the development of basic SSPF functionality, but also of the many extensions and additions.

• A large part of the effort went toward modeling. Since models are highly reusable, the current and future cost savings are considerable.

• SSPF offers a high degree of end-user programmability, eliminating the need for highly paid software experts.

• The biggest cost savings from SSPF accrue from the fact that using models produces highly integrated software. This results in large cost savings in software maintenance, upgrades, and, most importantly, in software integration, as demonstrated by our experiences at a different manufacturing site, i.e., at Wilmington, DE.

Wilmington Installation

In September 1997, Saturn installed SSPF at another plant. The pilot installation modeled 45 processes and their buffers, and it took four staff weeks to complete this modeling and some minor changes in the SSPF runtime system. Software support personnel made only one trip to to this plant to install the system.

It took three hours to install the system and bring it up. From that point onward, real-time data and historical data were available, which enabled team members at the plant to visualize and analyze the production flow. Since then, a total of about 100 processes have been modeled in about six staff weeks of effort. This effort did not require changes to the SSPF software or the services of software experts. This experience clearly shows the benefits, usefulness, and suitability of MIC for large-scale information systems.