E4-19. Activity analysis Farrah Westin plans to build a concrete walkway for her home during her vaca- tion. The following schedule shows how project time will be allocated: Hours Activity Purchase materials. ... Obtain rental equipment. Remove sod and level site Build forms for concrete. Mix and pour concrete into forms Level concrete and smooth Let dry.... Remove forms from concrete. Return rental tools ... Clean up. 5 2 20 10 5 6 24 2 1 4 a. Identify the value-added activities. How much of the total time is value-added time? b. Identify the non-value-added activities. How much total time is spent performing non-value- added activities? c. Calculate the manufacturing cycle efficiency