Flyer,
Keeping an eye on changes in free cash flow* would be more appropriate than PE over the short term, IMO.
*Edit: Free cash flow is the measure of the cash that is available from business operations, after the payment of interest and tax, for distribution in the form of dividends or for re-investment in the business. The proceeds of disposals and the cost of acquisitions, together with any substantial integration costs associated with them, are excluded from the calculation.