COTS items have several advantages, but they also have disadvantages. The presentation below shows the benefits, economics and drawbacks of using COTS products:
It is up to you: Complete the following exercise and review the benefits and drawbacks of using COTS.
NASA and COTS Success
NASA has shared a number of factors it found key to its success:
- Establishment of a clear design philosophy favoring the use of COTS products. NASA adopted an “80-20 rule” that stated that if a COTS or Government off the Shelf (GOTS) product met 80% of the functional requirements, it would be adopted pending final approval for deferring the remaining 20% of requirements;
- Employment of a software architecture that supported upgrading or replacing components without destroying the integrity of the system. NASA accomplished this by encapsulating COTS and GOTS products behind abstract interfaces that minimize the effect on other system components when a product or the way it is used changes;
- Development of clear component-selection criteria that allowed it to make COTS and GOTS selections efficiently, but emphasized hands-on use as the final arbiter for product selection. Products that passed the initial selection but failed the hands-on evaluation were quickly dropped;
- NASA hired experts who were knowledgeable about the new products to train personnel in design and implementation;
- Reevaluation of COTS and GOTS products at each product release. The project has found that some products were successful in the Control Center System (CCS) from their initial selection, some were failures and were replaced, and many fell in between. NASA performs periodic reassessments and reevaluations of COTS and GOTS products to replace under-performing products with better ones to improve system capability and long-term viability;
- Several more success examples from the DoD and NASA include:
- Acoustic system submarine replacement;
- Airborne Warning and Control System (AWACS) mission computer upgrade.
Word of caution: Use of COTS in NASA and DoD systems does not in any way negate the need to engineer, develop, integrate, test, evaluate, deliver, sustain, and manage the overall system. Particular attention should be paid to the intended usage environment and understanding the extent to which this differs from the commercial usage environment.
A project manager can not become complacent with simply purchasing a multitude of COTS items for use without proper analysis and special integration considerations since now integration encompasses the multiple COTS components into one deployable system! When acquiring COTS software products or other commercial items, the program manager still implements all systems engineering (SE) processes (See the SE module on AAQ for more information on SE).
Ultimately the project manager, not the vendors of the procured COTS products, is responsible for success.
COTS Best Practices
There is a list of best practices that apply to commercial items. Click on each blue spot to learn about them:
Since the marketplace is constantly changing, activities that involve more sustainable procedures must be implemented. These activities are especially important to manage prior to initial system delivery so there is no lag in terms of manufacturing and production. In turn this will also lead to more logistics involvement.
Some form of reorganization and reengineering will be ongoing throughout the life cycle at nearly all times. See the lessons learned section of this module for some extra reading material on COTS lessons learned.