The product life cycle concept suggests that a product passes through four stages of evolution: introduction, growth, maturity and decline. As the product evolves and passes through these four stages, profit is affected, and different strategies have to be employed to ensure that the product is a success within its market, therefore there is a need to define in time in which of the stages the product is at the moment. The blackboard architecture can be successfully used for the definition of the stages in product life cycle. The blackboard architecture was originally designed as a methodology aimed to handle complex, ill-defined problems. The first famous example - the Hearsay II speech recognition system appeared about 30 years ago. Most blackboard architectures can be modelled using C++, Java or LISP programming languages. This paper presents an overview of different authors’ works with proposed programming languages and systems for blackboard architecture implementation. Knowledge sources of the proposed blackboard architecture consist of rules for product life cycle stage definition. The paper also presents a programmed and tested system of blackboard architecture for checking work of rules that can be used for product life cycle stage definition.