In history what was Plan 17 what was the reason behind it and why did it fail?

In 1913 General Ferdinand Foch and General Joseph Joffre devised a strategic plan for the invasion of Germany. Plan 17 proposed French Army advances into Lorraine and Ardennes. On the outbreak of the First World War, the French Army carried out Plan 17. After initial success at both Lorraine and Ardennes, strong German resistance and the success of the Schlieffen Plan, resulted in orders being given by General Joseph Joffre on 24th August to retreat back to France.