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1.040/1.401 Project Management Spring 2007 Lecture 9 Deterministic Planning Part II. Dr. SangHyun Lee. lsh@mit.edu. Department of Civil and Environmental Engineering Massachusetts Institute of Technology . Project Management Phase. DESIGN PLANNING . DEVELOPMENT. OPERATIONS . CLOSEOUT.
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1.040/1.401Project ManagementSpring 2007Lecture 9Deterministic Planning Part II Dr. SangHyun Lee lsh@mit.edu Department of Civil and Environmental Engineering Massachusetts Institute of Technology
Project Management Phase DESIGN PLANNING DEVELOPMENT OPERATIONS CLOSEOUT FEASIBILITY Fin.&Eval. Organization Risk Estimating Planning & Scheduling
Outline • Network Techniques • CPM • PDM • Linear Scheduling Method
Precedence Diagram Method (PDM) Gantt chart A (10) B (10) Activity B will start right after Activity A finishes CPM (AON) A 10 B 10 A (10) Activity B will start right after Activity A starts B (10)
Precedence Diagram Method (PDM) • PDM Extends CPM to include • Multiple relationships beyond Finish-to-Start • Finish-to-Finish • Start-to-Start • Start-to-Finish
PDM – Types of Relationships A B • FS Finish-to-start • SS Start-to-start • FF Finish-to-finish • SF Start-to-finish A B A B A B
Precedence Diagram Method (PDM) Gantt chart A (10) B (10) Activity B will start after Activity A finishes CPM (AON) A 10 B 10 A (10) Activity B will start 5 days later after Activity A finishes (5) B (10) A 10 A’ 5 B 10
Precedence Diagram Method (PDM) • PDM Extends CPM to include • Lag (+) & Lead (-) A (10) FS (+5) B (10) A (10) FS (-5) B (10)
PDM Relationships w/ Lag & Lead Lay-Out & Excavate Finish-to-StartLead Finish-to-StartLag Start-to-StartLead Start-to-StartLag Install Fuel Tanks FS -1 Pour 4th-Floor Slab Remove 4th Floor Shoring FS +14 SS -1 Backfill Pipe Install Pipe Install Fuel Tanks Install Exterior Conduits SS +1 Adapted from: Callahan et al., 1992
Form Slab on Grade FF -1 Reinforce Slab on Grade Excavate Trench FF +3 Lay Pipe Approve SF -1 Prepare Wall Shop Drawings SF +10 Install Wood Paneling & Base Install Carpeting PDM Relationships w/ Lag & Lead Finish-to-FinishLead Finish-to-FinishLag Start-to-FinishLead Start-to-FinishLag Adapted from: Callahan et al., 1992
Slack or Float in PDM • Total Float (TF) • TF(k) = LF(k) - ES(k) - Dk • Start Float (SF) • SF(k) = LS(k) - ES(k) • Finish Float (FNF) • FNF(k) = LF(k) - EF(k)
PDM Example 30 10 1 C GC A GC 2 3 3 40 80 90 100 D EL H ME K ME FINISH 2 6 2 0 1 1 ES EF START LS LF D TF SF FNF 20 50 B GC E ME 4 4 60 70 2 F GC G EL 6 3 Source: Callahan et al., 1992
Forward Pass 30’s ES = 10’s EF + Lag (FS) 30 10 1 3 6 0 4 C GC A GC 2 3 3 40 80 90 100 D EL H ME K ME FINISH 2 6 2 0 1 1 0 0 START LS LF D TF SF FNF 20 50 4 0 B GC E ME 4 4 60 70 2 F GC G EL 6 3 Source: Callahan et al., 1992
Forward Pass 30 10 1 3 6 0 4 C GC A GC 100’s ES = 90’S EF 100’s ES = 70’s EF MAX 2 3 3 40 80 90 100 17 17 15 9 9 17 7 15 D EL H ME K ME FINISH 2 6 2 0 1 1 0 0 START LS LF D TF SF FNF 20 50 4 0 8 4 B GC E ME 4 4 60 70 2 15 12 12 6 F GC G EL 6 3 Source: Callahan et al., 1992
Backward Pass 30 10 1 3 6 0 4 C GC A GC 2 3 3 40 80 90 100 17 17 15 9 9 17 7 15 D EL H ME K ME FINISH 9 17 17 17 15 15 2 6 2 0 1 1 0 0 START D TF SF FNF 20 50 4 0 8 4 B GC E ME 4 4 60 70 2 15 12 12 6 F GC G EL 17 14 70’s LF = 100’S LS 70’s LS = 80’s LF - 1 6 3 MIN Source: Callahan et al., 1992
Backward Pass 30 10 1 3 6 0 4 C GC A GC 0 4 3 6 2 3 3 40 80 90 100 17 17 15 9 9 17 7 15 D EL H ME K ME FINISH 9 7 17 17 9 17 15 15 2 6 2 0 1 1 0 0 START 0 0 D TF SF FNF 20 50 4 0 8 4 B GC E ME 9 1 5 5 4 4 1’s LF = 10’S LS 1’s LF = 20’s LS 60 70 MIN 2 15 12 12 6 F GC G EL 8 17 14 14 6 3 Source: Callahan et al., 1992
Total Slack or Float 30 10 1 3 6 0 4 C GC A GC 0 4 3 6 TS or TF = LF - ES - D 2 0 0 3 3 40 80 90 100 17 17 15 9 9 17 7 15 D EL H ME K ME FINISH 9 7 17 17 9 17 15 15 2 6 0 2 0 0 0 0 1 1 0 0 START 0 0 D 0 SF FNF 20 50 4 0 8 4 B GC E ME 9 1 5 5 4 4 1 1 60 70 2 15 12 12 6 F GC G EL 8 17 14 14 6 3 2 2 Source: Callahan et al., 1992
Critical Path 30 10 1 3 6 0 4 C GC A GC 0 4 3 6 2 0 0 3 3 40 80 90 100 17 17 15 9 9 17 7 15 D EL H ME K ME FINISH 9 7 17 17 9 17 15 15 2 6 0 2 0 0 0 0 1 1 0 0 START 0 0 D 0 SF FNF 20 50 4 0 8 4 B GC E ME 9 1 5 5 4 4 1 1 60 70 2 15 12 12 6 F GC G EL 8 17 14 14 6 3 2 2 Source: Callahan et al., 1992
Start & Finish Slack or Float 30 10 1 3 6 0 4 C GC A GC 0 4 3 6 2 0 0 3 0 0 0 0 3 40 80 90 100 17 17 15 9 9 17 7 15 D EL H ME K ME FINISH 9 7 17 17 9 17 15 15 2 6 0 2 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 START 0 0 D 0 0 0 20 50 4 0 8 4 B GC E ME 9 1 5 5 4 4 1 1 1 1 1 1 60 70 2 15 12 12 6 F GC G EL 8 17 14 14 6 3 2 2 2 2 2 2 Source: Callahan et al., 1992
PDM Caveat: Vanishing Critical Path • Tracing critical path can be difficult • Finish-finish constraints with leads can lead to “vanishing” critical path FF -5 Total float Duration
PDM Caveat - Counter-Intuitive • Tracing critical path can be difficult • Can be counter-intuitive • The longer A20 is, the smaller the critical path duration and quicker can complete! A30 FF 2 A20 SS 0 A10
Slack or Float “Ownership” • Tension between owner and contractor • Significant legal implications • Problem: • Owners seek to push contractors on tight schedule • Too many late starts risk overall project duration • Contractors seek flexibility • Flexibility has value
Outline • Network Techniques • CPM • PDM • Linear Scheduling Method
Linear Scheduling Method (LOM) • Line-of-Balance • Time + Location • Repetitive Linear Activities • Rate of Progress (production rate)
LSM Diagram Source: Callahan et al., 1992
Plotting Activity Progress Lines Source: Callahan et al., 1992
Use of Restraint on LSM Diagram Source: Callahan et al., 1992
Activity Interference Source: Callahan et al., 1992
Use of Activity Buffers in LSM Schedules Source: Callahan et al., 1992
LSM – Example LinearPlus
LSM – Example Tilos