OM480 Defining the Project Parameters – Scheduling 101 (With Material from the Text Authors)
Overview Scheduling Precedence Relationships PERT/CPM Critical Chain Activity Networks
Scheduling Project = Problem scheduled for solution Requires: –Planning –Organizing –Coordinating –Directing –Controlling gninnalP drawkcaB Forward Execution
Project Management Trade-Offs Performance Quality CostTime
© Project Priority Matrix Constrain Enhance Accept TimePerformanceCost
WBS/Work Packages to Network Circuit board Design cost account Production cost account Test cost account Software cost account Lowest element OrganizatioUnitsOrganizatioUnits Design WP D-1-1 Specifications WP D-1-2 Documentation Production WP P-10-1 Proto 1 WP P-10-2 Final Proto 2 Test systems WP T-13-1 Test Software WP S-22-1 Software preliminary WP S-22-1 Software final version B Proto 1 5 D Final proto 2 4 A Specifications and documentation 2 C Preliminary software 3 F Final software 2 K Test 3 A D-1-1 D-1-2 B P-10-1 D P-10-2 F S-22-2 K T-13-1 C S-22-1
Duration and Activities Effort is not duration –Time spent in actual “work” Duration lasts longer –Elapsed time from activity start to finish –Imagine “NFL two-minute warning” See Page for techniques Realities of Duration Planning –Deliveries –Breakdowns/Repairs –Approvals
PERT –Program Evaluation and Review Technique –US Navy “Polaris Missile” Program – 1950s –Statistical manipulation of 3 duration estimates Most Optimistic Most Likely Most Pessimistic –Probability-based P(MO) + P(ML) + P(MP) = Duration –More reflective of “realities”
CPM –Critical Path Method –DuPont and Remington Engineers – 1950s New Product/Process Roll-out –Less sophisticated than PERT –Relies on one duration estimate –Same duration techniques as PERT
Hypothetical Network
Activity and Project Frequency Distributions ACTIVITYPROJECT a m b TE (A)(B)
PERT Activity Calculation T(e) = a + 4m + ba = Most Optimistic (MO) 6m = Most Likely (ML) b = Most Pessimistic (MP) T(e) = Activity Duration When Probabilities are “Unknown” or too lazy/scared To calculate!!!
Possible Project Durations T E =64 T S =67
PERT Schedule Probability Z is derived from a table of predetermined probabilities Z = T(S) – T(E)Z = Probability of SD(T[E]) 2 Meeting Schedule T(S) = Scheduled Duration T(E) = Critical Path Duration
PERT Simulation Activity Times and Variances Activity ambt(e)
Activity ambt(e) [(b-a)/6]2 Var
Hypothetical Network T E =62 Calculate t(e) and Z for this network……
Z Table Z ValueProbabilityZ ValueProbability
Activity Networks Flowchart-based representation of activities –Sequenced –Precedence Consecutiveness Concurrency Activity on Node –Action is in the “box” Activity on Arrow –Activity is on the “line”
Critical Chain Based on “Theory of Constraints” –Eliyahu Goldratt “The Goal”
Rollup of Network Plans WP-2 A B C D E F WP-1 WP-4 WP-3 Level 1 - Milestone Plan Level 2 - Plans Level 3 - Plans
Air Control Inc., Custom Order Project—Gantt Chart Order review Design custom parts Order standard parts Produce standard parts Software development Manufacture custom hardware Assemble Test
Software Conversion Project Responsibility Matrix Activities Organization Unit/Individual Legend R = Responsibility C = Contributes A = Advises
Air Control Inc., Custom Order Project—Network Diagram 1 Order review Software development Order standard parts Produce standard parts Design custom parts Manufacture custom hardware Assemble Test Activity 8 # Legend Duration ES EF LS LF
© Air Control Inc., Custom Order Project—Network with Dates 1 Order review 2 1-Jan 2-Jan 1-Jan 2-Jan Software development Order standard parts Produce standard parts Design custom parts 18 2-Jan 20-Jan 22-Jan 9-Jan 15 2-Jan 17-Jan 15-Jan 30-Jan 10 2-Jan 12-Jan 5-Jan 15-Jan 13 2-Jan 15-Jan 2-Jan 15-Jan 6 78 Manufacture custom hardware Assemble Test Activity 8 # Legend Jan 30-Jan 15-Jan 30-Jan Jan 9-Jan 30-Jan 9-Jan 5 9-Jan 14-Jan 9-Jan 14-Jan Duration ES date EF date LS date LF date
AOA Network Building Blocks 8079 Install software EventActivity
Partial Koll Business Center AOA Network A Application approval D Service availability check C Traffic study B Construction plans
Partial AOA Network Koll Network A X C B E (A) A B C X E (B) A B X C E (C)
Partial AOA Network Koll Network A B C X E (D) 5 D A B C X E (E) 5 D F ?
Activity-on-Arrow Network KOLL BUSINESS CENTER County Engineers Design Department A5A5 B C 10 X Y F 10 G 170 H 35 E 15 D5D5 Activity Duration Legend
Activity-on-Arrow Network Forward Pass KOLL BUSINESS CENTER County Engineers Design Department A5A5 B C 10 X Y F 10 G 170 H 35 E 15 D5D5 Legend EF
Activity-on-Arrow Network Backward Pass KOLL BUSINESS CENTER County Engineers Design Department A5A5 B C 10 X Y F 10 G 170 H 35 E 15 D5D5 Legend LS EF
Activity-on-Arrow Network Backward Pass, Forward Pass, and Slack KOLL BUSINESS CENTER County Engineers Design Department A5A5 B C 10 X Y F 10 G 170 H 35 E 15 D5D5 Legend LS EF
Air Control Inc., Custom Order Project— AOA Network Diagram Order review Software development Order standard parts Produce standard parts Design custom parts Manufacture Custom Hardware Assemble Test Legend Dur. ES EF LS LF
Activity-on-Node Network Fundamentals X Y Z Y and Z are preceded by X Y and Z can begin at the same time, if you wish (B) ABC A is preceded by nothing B is preceded by A C is preceded by B (A) J K L M J, K, & L can all begin at the same time, if you wish (they need not occur simultaneously) All (J, K, L) must be completed before M can begin but XZ AA Y (C) (D) Z is preceded by X and Y AA is preceded by X and Y
Activity-on-Node Network Fundamentals KOLL BUSINESS CENTER County Engineers Design Department EF
Activity-on-Node Network Forward Pass EF KOLL BUSINESS CENTER County Engineers Design Department
Activity-on-Node Network Backward Pass LS KOLL BUSINESS CENTER County Engineers Design Department
Activity-on-Node Network with Slack LS EF KOLL BUSINESS CENTER County Engineers Design Department
Example of Laddering Using Finish-to-Start Relationship Trench 1/3 Lay pipe 1/3 Refill 1/3 AON network
Finish-to-Start Relationship XY Lag 2
Start-to-Start Relationship Activity M Activity N Activity P Activity Q Lag 5 A B
Use of Lags to Reduce Detail Trench 1 mile Lay pipe 1 mile Lag 3 Refill 1 mile Lag 3
Finish-to-Finish Relationship Lag 4 Prototype Testing
Start-to-Start Relationship Lag 3 System documentation Testing
Combination Relationships Lag 2 Code Debug Lag 4
Network Using Lags Legend Lag 5 Lag 10 Lag 5 Lag 10
Hammock Activity Example Legend