focusing on past sales Trends is problematic when attempting to assess the value of a strategy because; acquiring accurate sales data different due to departmental security, sales data Change Daily this thus makingforecasting erratic, it does not consider creative actions taken by managers of possible actions taken by competitors, Trend analysis requires between $5$ and $10$ years worth of data before reliable regression lines can be established, fluctuations in Market discount rates across years render year to year sales comparisons meaningless