Abstract: Elders often have difficulties in daily activities because of declining cognitive ability. Assisting elders with information technology has become a new and challenging research area. It's a problem that how to predefining activities into a plan and prompting the elders if they fail to execute it in this area. We gave a more flexible way to present the time constraints of activities based on the traditional way, but as the same time how to resolve the conflicts between activities become a new troublesome problem. I}he concept and theory of "Simple Temporal Constraint Network"(STCN) was then proposed, which will well handle the problem. We presented the time constraints of activities with STCN and checked the STCN's consistency. The "General Checking Algorithm"(GCA) was adopt,but we found that the GCA's complexity will increase by exponentially if the number of activities increases. Then, we gave an improved algorithm to resolve the conflicts between activities and compared the two algorithms. The experiment result shows the ICA has better performance than GCA.

Key words: Activity planning, Temporal constraint, Simple temporal constraint network, Consistency