1.040/1.401/ESD.018 Project Management

1. 1.040/1.401/ESD.018Project Management LECTURE 13 RESOURCE ALLOCATION PART 3 Integer Programming Analyzing Queues in Project Management Sam Labi and Fred Moavenzadeh Massachusetts Institute of Technology

2. Queuing Systems I Today’s conversation … Integer Programming as a Tool for Resource Allocation in Project Management - Activities only - Activities and Resources Queuing in Project Management - Examples of Queuing Systems - Components of a Queuing System - The Capacity of a Queue - Queuing System Performance - Attributes of a Queuing System

3. PART 1 Integer Programming for Resource Allocation in Project Management

4. Consider the Following Simple Project Activity Diagram (Activities Only) X3 X2 X1 X6 X4 X5 • Types of relationships • Complementary: Xi should be done with (before or after Xj) • Substitutionary: Either Xi must be done or Xj must be done. • Precedence: Xi must be done before Xj • Xi must be done after Xj) • 4. Mandatory: Xi must be done “no matter what”

5. Benefit = bX2 Cost = cX2 Benefit = bX3 Cost = cX3 X3 X2 X6 X1 Benefit = bX6 Cost = cX6 Benefit = bX1 Cost = cX1 X4 X5 Benefit = bX5 Cost = cX5 Benefit = bX4 Cost = cX4

6. Examples of Benefits: Equipment Utilization (%), Labor Utilization, etc. Benefit = bX2 Cost = cX2 Benefit = bX3 Cost = cX3 X2 X3 X6 X1 Benefit = bX6 Cost = cX6 Benefit = bX1 Cost = cX1 X4 X5 Benefit = bX5 Cost = cX5 Benefit = bX4 Cost = cX4

7. Examples of Benefits: Equipment Utilization (%), Labor Utilization, etc. Examples of Costs: Monetary ($), Duration (days), etc. Benefit = bX2 Cost = cX2 Benefit = bX3 Cost = cX3 X2 X3 X6 X1 Benefit = bX6 Cost = cX6 Benefit = bX1 Cost = cX1 X4 X5 Benefit = bX5 Cost = cX5 Benefit = bX4 Cost = cX4

8. Examples of Benefits: Equipment Utilization (%), Labor Utilization, etc. Examples of Costs: Monetary ($), Duration (days), etc. Useful to convert all benefits and cost into a single unit Benefit = bX2 Cost = cX2 Benefit = bX3 Cost = cX3 X2 X3 X6 X1 Benefit = bX6 Cost = cX6 Benefit = bX1 Cost = cX1 X4 X5 Benefit = bX5 Cost = cX5 Benefit = bX4 Cost = cX4

9. Examples of Benefits: Equipment Utilization (%), Labor Utilization, etc. Examples of Costs: Monetary ($), Duration (days), etc. Useful to convert all benefits and cost into a single unit Scaling, Metricization Benefit = bX2 Cost = cX2 Benefit = bX3 Cost = cX3 X2 X3 X6 X1 Benefit = bX6 Cost = cX6 Benefit = bX1 Cost = cX1 X4 X5 Benefit = bX5 Cost = cX5 Benefit = bX4 Cost = cX4

10. X3 X2 X1 X6 X4 X5

11. X3 X2 X1 X6 X4 X5

12. X3 X2 X1 X6 X4 X5

13. X3 X2 X1 X6 X4 X5

14. Some Mathematical Notations and Formulations • Constraints • Objective function

15. (a) Constraints

16. X3 X2 X1 X6 X4 X5

17. X3 X2 X1 X6 X4 X5 Xi = 1,0 i = 1,2,…,6

18. X3 X2 X1 X6 X4 X5 Xi = 1,0 i = 1,2,…,6 Integer programming formulation. Carry out Activity i or do not.

19. X3 X2 X1 X6 X4 X5 X1 = 1 Activity 1 is mandatory

20. X3 X2 X1 X6 X4 X5 X6 = 1 Activity 6 is mandatory

21. X3 X2 X1 X6 X4 X5 Carry out Activity 2 or 4 but not both. ?

22. X3 X2 X1 X6 X4 X5 X2 + X4= 1 Carry out Activity 2 or 4 but not both.

23. X3 X2 X1 X6 X4 X5

24. X3 X2 X1 X6 X4 X5 The average benefit of all selected activities should be at least b*

25. X3 X2 X1 X6 X4 X5 The average cost of all selected activities should not exceed c*

26. X3 X2 X1 X6 X4 X5 The least benefit of any selected activity should be b* OR No activity selected should have a benefit that is less than b*

27. X3 X2 X1 X6 X4 X5 The highest cost of any selected activity should be c* OR No activity selected should have a cost that is more than c*

28. (b) Objective Function

29. Objective Function What is our goal? What are we seeking to maximize/minimize? Maximize the sum of all benefits E.g. The set of activities that involve the lowest total duration Minimize the sum of all costs E.g. The set of activities that involve the least resources Maximize all benefits and minimize all costs

30. Objective Function What is our goal? What are we seeking to maximize/minimize? Maximize the sum of all benefits E.g. The set of activities that involve the lowest total duration Minimize the sum of all costs E.g. The set of activities that involve the least resources Maximize all benefits and minimize all costs OBJ = B + (– C) Linear additive

31. Objective Function What is our goal? What are we seeking to maximize/minimize? Maximize the sum of all benefits E.g. The set of activities that involve the lowest total duration Minimize the sum of all costs E.g. The set of activities that involve the least resources Maximize all benefits and minimize all costs OBJ = B + (– C) Linear additive Linear additive, equal weight of 1 OBJ = 1B – 1C

32. Objective Function What is our goal? What are we seeking to maximize/minimize? Maximize the sum of all benefits E.g. The set of activities that involve the lowest total duration Minimize the sum of all costs E.g. The set of activities that involve the least resources Maximize all benefits and minimize all costs OBJ = B + (– C) Linear additive Linear additive, equal weight of 1 OBJ = 1B – 1C OBJ = wBB – wCC Linear additive, non-equal weights

33. Objective Function What is our goal? What are we seeking to maximize/minimize? Maximize the sum of all benefits E.g. The set of activities that involve the lowest total duration Minimize the sum of all costs E.g. The set of activities that involve the least resources Maximize all benefits and minimize all costs Linear additive OBJ = B + (– C) Linear additive, equal weight of 1 OBJ = 1B – 1C Linear additive, non-equal weights OBJ = wBB – wCC Linear multiplicative

34. EXTENSION OF THE PROBLEM TO RESOURCE ALLOCATION

35. EXTENSION OF THE PROBLEM TO RESOURCE ALLOCATION X2 X3 X1 X6 X4 X5 Previous formulations: X represents an activity

36. EXTENSION OF THE PROBLEM TO RESOURCE ALLOCATION 1 2 3 4 5 J X2 X3 X2 X3 X1 X1 X6 X6 X4 X5 X4 X5 New formulations (Resource Allocation formulations): X represents an activity+resource bundle Previous formulations: X represents an activity

37. EXTENSION OF THE PROBLEM TO RESOURCE ALLOCATION 1 2 3 4 5 J Resources Xij is a Resource-activity pair Resource j is allocated to Activity i Activities: i = 1, 2, … I Resources: j = 1, 2, … J X23 means Resource 3 is allocated to Activity 2 X55 means Resource 5 is allocated to Activity 5 X23 X31 X15 X64 X44 X55 New formulations (Resource Allocation formulations): X represents an activity+resource bundle

38. EXTENSION OF THE PROBLEM TO RESOURCE ALLOCATION 1 2 3 4 5 J Resources What if more than one resource is allocated to an activity? Example, Resources 3 and 5 are allocated to Activity 5 Means that X55 and X53 should exist in the mathematical formulation. X23 X31 X15 X64 X55 X44 X53

39. EXTENSION OF THE PROBLEM TO RESOURCE ALLOCATION • Again, let’s see some Mathematical Notations and Formulations • Constraints • Objective function

40. (a) Constraints

41. X31 X23 X15 X64 X44 X55

42. X23 X31 X15 X64 X44 X55 Xij = 1,0 i = 1,2,…, Ij = 1,2,…, J

43. X31 X23 X15 X64 X44 X55 X15 = 1 Resource-Activity Pair 1-5 definitely needs to be carried out

44. X31 X23 X15 X64 X44 X55 X23 + X44 = 1 Carry out Resource-Activity Pairs 2-3 or 4-4 but not both.

45. X31 X23 X15 X64 X44 X55 The average benefit of all selected Resource-activity pair should be at least b*

46. X31 X23 X15 X64 X44 X55 The average cost of all selected Resource-activity pairs should not exceed c*

47. X31 X23 X15 X64 X44 X55 The least benefit of any selected Resource-activity pair should be b* OR No Resource-activity pair selected should have a benefit that is less than b*

48. X31 X23 X15 X64 X44 X55 The highest cost of any selected Resource-activity pair should be c* OR No Resource-activity pair selected should have a cost that is more than c*

49. (b) Objective Function

50. Objective Function What is our goal? What are we seeking to maximize/minimize? Maximize the sum of all benefits E.g. The set of resource-activity pairs that involve the lowest total duration Minimize the sum of all costs E.g. The set of resource-activity pairs that involve the least resources Maximize all benefits and minimize all costs