To locate relevant information within an vast array of potentially irrelevant information, a graphical user interface supported by visual navigation search cues may be useful. Because few studies have reported effects of visual cues in complicated workplace conditions, this study examined effects of valid/invalid cues on performance in a search task that simulated central monitoring task. Reaction times (RTs) to targets were measured for valid/invalid cues relative to no-cue conditions. Results indicated that cost (increment of RT by the invalid cue) is less than benefit (decrement of RT by the valid cue). Subsequently, to examine effects of cues in a perception/cognition phase, rates of correct answers were measured by eliminating an action phase of the search task. Results reveal the benefit (higher rate of correct answers in the valid cue condition than in the no-cue condition) was greater than the cost (lower rate of correct answers in the invalid cue condition than in the no-cue condition). Additionally, eye movement data indicated that onset times of eye fixation to a cued button were concentrated within 200-300ms regardless of cue condition. Together, results suggest that in a complicated search situation, such as a central control system, the costs for relying on invalid cues can be expressed as 1/d, with d as the number of candidates of search. This implies that as d increases the usefulness of a predictive (valid) cue increases.