No1 Rule - don't buy too much cement on your site because some of the cement will grow legs and wings and secretly walk and fly away.
No2 - your project manager will automatically become a cement ven for.
No3 - you will rebuy the cement you already bought making it the worst thing to happen to anyone..
No 4- Verify well before choosing your Project manager to avoid excessive expenditure.
Once you apply these rules, you will see that your work will move smoothly without any much additional expenses.