Under constant value investing you decide to perhaps invest $10,000 in a stock and at your review dates if the stock value is say $12000 then you sell $2000 of stock to bring the stock value back down to $10,000 again.
Similarly if the stock value declined to $8000 you add $2000 worth of stock.
Buy-low, sell-high.
In MyWay I believe the trade timing is also based on some TA measures (perhaps standard deviation/Bollinger Band type indicators). You can also assign SAFE like controls (but they are called different names).