Time Management Week 7 Learning Objectives You should

Time Management Week 7 - Learning Objectives You should be able to: n List and describe the processes, activities, inputs, and outputs in time management n Create and interpret a network diagram n Create and interpret a GANTT chart n Define and use: CPM, critical path and time, slack time, crash time, fast-tracking

Time Management Issues n Frequent source of project failure – Often used as a success measure n n Frequent source of project conflict Time / cost / scope tradeoffs Less negotiable, least flexibility Stakeholder involvement – communication and commitment

Time Management Processes n Define Activities – further defines scope n Sequence Activities – further defines time n Estimate Duration – further defines cost Develop Schedule n Control Schedule n

Activity n Element of work - on WBS – cost – duration – resources n “Tasks” vs. “activities”? – Doesn’t matter, as long as the work to be done is described accurately and understood by those who must do the work

Define Activities n n Steps needed to produce deliverables Inputs: – WBS, Scope, historical data, constraints, assumptions n Outputs: – Activity list, descriptions, supporting detail, updates to WBS – complete understanding of work involved

Sequencing Activities n Identifying dependencies – relationships between activities n Mandatory dependencies – technical, defined by type of work n Discretionary dependencies – defined by project team n External dependencies – relationships to non-project activities

Activity Sequencing Tools n Network diagrams – schematic display of activities and dependencies – activity on arrow (AOA or ADM) n Precedence diagramming – activity on node (AON or PDM)

D (15) 6 2 A (20) 1 B (20) J (8) E (10) F (14) 3 G (4) C (10) 4 H (11) 7 I (18) 5

Precedence Diagram (PDM) n n Boxes represent activities Types of dependencies: – finish-to-start – start-to-start (can be parallel) – finish-to-finish (can be parallel) – start-to-finish (rarely used)

Estimating Duration n n Should involve stakeholders, people doing the work Inputs: – – n Activity list, constraints, assumptions Resource requirements Resource capabilities (human and materials) Use historical data, previous projects, experience, simulations Outputs: duration estimates – quantitative assessments of likely number of work periods required to complete activity

Developing the Schedule n Inputs to schedule development: – project network diagram – activity duration estimates – resource requirements – resource pool description – calendars (project and resource) – constraints, assumptions, leads and lags

Scheduling Tools n n GANTT charts CPM: Critical Path Method PERT: probabilistic time estimation Simulation

GANTT Chart n n n shows planned vs. actual progress multiple tasks on horizontal time scale easy to read, easy to construct monitoring and control of progress requires frequent updating limited display of dependencies

Components of GANTT Chart n n n Activities - scheduled and actual Precedence relationships Milestones (identifiable points in project) – usually represents reporting requirements – usually corresponds to critical events n n n Can add budget information Does not show technical interdependencies Need network diagram to interpret, control, and compensate for delays

Gantt Chart symbols n Milestone: – diamond n Summary task: – dark bar n Individual task: – light bar n Arrows: – dependencies

CPM Definitions n Activity: uses resources and takes time n Event: result of completing an activity – has identifiable end state at a point in time n n n Network: combined activities & events in a project Path: series of connected activities Critical: activities, events, or paths which, if delayed, will delay project completion n Critical path: sequence of critical activities from start n to finish Node: start or end of an activity Arrow (Arc): shows path n

A-C-F = 19 B-E = 9 A, 5 2 C, 6 4 D, 2 1 B, 4 3 B-D-F = 14 F, 8 Critical Path is 5 E, 5 A-C-F Critical Time 19

n EOT: – earliest occurrence time for event – time required for longest path leading to event n n LOT: latest occurrence time for event EST: earliest starting time for activity LST: latest starting time for activity Critical time: shortest time in which the project can be completed n Slack time: difference between earliest and latest start times

D (15) 6 2 A (22) 1 B (20) J (8) E (10) F (14) 3 G (4) C (10) 4 H (11) 7 I (18) 5

n What is the critical path? Critical time? – B-F = 34 – B-E-J = 38 – A-D-J = – B-G-I = – C-H-I = n n What is the earliest occurrence time of event 6? What is the latest start time for activity F?

Probabilistic Time Estimation n n More realistic, includes uncertainty Expected completion time – optimistic, pessimistic, most likely times n take weighted average of the 3 times TE = (a + 4 m + b)/6 n n uncertainty = variance (range of values) Probability of completion of project in desired time D Z = (D - ì)/(sqrt(ó 2 ì))

Outputs of Scheduling Process n n n Date-enhanced project network diagram GANTT charts, milestone charts Time-scaled network diagrams – combines GANTT, network diagram n n Supporting detail Schedule management plan

Shortening the Schedule n n Duration compression Crashing: – time/cost tradeoff n Fast tracking: – parallel vs. sequential n Resource loading and leveling: – more even distribution of resource usage

Slope = (crash cost - normal cost ) (crash time - normal time) = cost per day of crashing activity

Schedule Control n n Determining, managing schedule changes Influencing changes so they are beneficial Inputs: – schedule, performance reports, change requests, schedule management plan Outputs: – schedule updates & notification – corrective action to minimize delays – lessons learned

Controlling Schedule Changes n Involve stakeholders – manage expectations – progress meetings – no surprises n Leadership, discipline, negotiation – review draft schedule and add details – realistic estimates – allow for contingencies – empower and incent employees n Proper use of tools