Lecture 07/08: Planning and Time Management

Question 1

Define project planning

Answer 1

The identification of the project objectives and the ordered activity necessary to complete the project including the identification of resource types and quantities required to carry out each activity or task

Question 2

Define Project scheduling + project schedule:

Answer 2

→ defines network logic for all activities (tasks either precede of follow other tasks in the PJ)

Project schedule: output of a schedule model that presents linked activities with dates/durations/miletstones/resources
→ network diagram is mainly used for sceduling

Question 3

What are serial and concurrent activities?

Answer 3

serial: flow from one to the next, in sequence

concurrent: when multiple activities can be done at the same time
→ parallel project paths are constructed

Question 4

Why use Network diagramm over Gantt Chart?

Answer 4

• ND shows a systemic PJ representation
• enablbes “what-if” analysis

-illustrates interdependence of all task and work packages
→ A before B
→ A and B at the same time

-illustrates interrelationship among activities and PJ personell and communication flows
→ relevant for Person A and B

-helps with master scheduling of organizational resources, shows time, when personnel must commit to an activity
→ companies have more than one PJ

-identifies critical activities

-determine when PJ expected to be done

• gives dates when PJ activities must start/end
• demonstrates activity dependency among each other

Question 5

What is a network?

Answer 5

-set of nodes linked by arrows, their sequence defina a path
→ if arrows have a sense, the network is called oriented

• usually flow from left to right
• activity can only begin when prior one is done
• each AC has a number
• single nodes are at the beginning/end

Question 6

What’s the difference in using “Activities on Nodes” instead of “Activities on Arrow” for scheduling?

Answer 6

AC on arrow:
→

Question 7

What is a Gantt chart + list its characteristics and limitations

Answer 7

-shows when the project and each activity start and end against a horizontal timescale (bar chart)

• easy to read/comprehend
• can be used as a tracking tool
• allow updating/controll PJ
• identifying resource needs + assigning ressource to tasks
• easy to create
• *Limitation:**
• “all PJ view” only good for PJ with few AC
• usually no indicaton of relationship between AC

Question 8

What are milestones?

Answer 8

-important events in a PJ

Question 9

What are sources to get AC duration info?

Answer 9

1. Experience
   -past examples or similar PJ (often best idea)
   → but assumptions are based on past and wont work today. PJ are effected by external event, which are always unique
   → must be aware of using distorted/outdated info
2. Expert opinion
   -past PJ manager/expert in an area
   → experts know the easiest paths, best contacts and fastest ways to complete someting. But would his estimation be valid for non-experts?
3. Mathematical derivation
   -duration probability based of best case, most likely case and worst case scenarios
   -popular increasing complex algorithms (data mining etc.)
   → you need to know what you are doing

Question 10

List precedence constraints among activities + examples and occurance

Answer 10

1. Natural
   → digging before building foundation
   → usually constant
2. Environmental
   → resource availability constraint (only have 1 excavator)
   → can be dynamic
3. Prefential
   →”i prefer eletrical work before mechanical one”
   → can but dynamic

Question 11

Define the PJ Sceduling Terms Path/Event/Node

Answer 11

Path → sequence of activities defined by the project network logic

Event → point when an activity is either started or completed

Node → defining points of a network; connector to some or all other paths

Question 12

Difference between Merge activity and burst activity

Answer 12

Merge: AC D can only beginn, when A,B and C are done

Burst: B,C and D can only beginn, when A is done

Question 13

What is total float?

Answer 13

Amount of time an activity may be delayed from its early start without delaying the finish of the PJ

Question 14

Define critical path:

Answer 14

path trough the PJ network with the longest duration

→ a delay for any activity belongign to the critical path implies a delay for the whole project

Question 15

Define Critical Path method

Answer 15

network analysis technique used to determine the amount of scedule flexibily on logical network path in PJ scedule networkt to determin minimum PJ duration

Question 16

List types of float

Answer 16

• total float
• free float
• independent float

Question 17

Define total float

Answer 17

-maximum interval available to postpone or extend the execution for a single activity, without chaning the project dealine

→ AC with TF of ≤0 are called “critical AC”

Add formular

Question 18

Define Free Float (FF)

Answer 18

float availabe for the AC without need to postpone the earliest start date for the successive node (k)

→ “the amount of time that a schedule AC can be delayed without delaying the early start date of any successor or violatiing a scedule constraint”

add formular

Question 19

Define independent float

Answer 19

Acceptable delay for an activity with the hypothesis that the starting date
was the latest start date and the finish activities (successive activity
starting) must be realized at the earliest start date. The independent float does not influence the previous and successive activities

Question 20

List some constrains on resources

Answer 20

• person cant work 8h a day on the same job
• maschinery: the excavator X cant be in two places in the same time
• space in the construction site/ office
• limits in the temporary accomodation

Question 21

When do we need to do “Crashing PJ”?

Answer 21

• we are late/need to recover → deadline cant be changed
• market needs change and PJ is in demand ealier than anticipated (e.g. competetor did similar PJ)

-PJ is behind schedule
→ only way to regain control

-contracts harm you when failing a deadline (penalties)

Question 22

How can u crash a PJ

Answer 22

1. Improving existing resoucres productivity
   -better plannig and organization of the PJ, eliminating barries to productivity liek bureaucracy
   -better motivation/productivity of the team
   → those things are better done before a PJ
   
   1. Changing work methos/resources
      -altering technology and types of resoucres employed
      -hiring senior personnel, contact personnel subcontractors for specific functions

Question 23

Crashing project with compromising quality and/or reducing PJ scope

Answer 23

• prioritizing/distinguish between “must-have” features of the PJ and add-ons
• functions that may not be critical to the PJ mission

-revisiting work breakdown structure and PJ schedule and making necessary modicfiations
→ Goal: minimizing negative effect on final deliver PJ
→ IRON TRIANGLE

Question 24

Chrashing PJ with Institute fast-tracking

Question 25

Crashing PJ with work overtime

Answer 25

-theory: workers work 40h, by adding 10h, productivity is increased by 20%

→ but for hourly workers, overtime rate are expensive

→ extra hours dont gurantee better result, the other way is more apparent

Question 26

Crashing PJ by increasing the quantity of resources

Answer 26

-might have the net effect of reducing amount of time to comples a task

→ BUT: learning curve is affected, by Brookes Law: adding resources delays ongoing AC just further.
→ INSTEAD: add them before starting an AC

-pay attention to fix durations (e.g. 1 woman -9month pregnant, add 1 woman, still 9 months)

Question 27

Explain the Time/Cost Trade-offs for crashing with a diagramm

Answer 27

• determine activity fixed/varible costs
• crash point is the fully expedited activity
• optimize time-cost tradeoffs
• shorten activities on the critical path

STOP when:

1. target completion time is reached
2. crashing cost exceed penalty cost

Question 28

Why should a company implement Quantative Risk Evaluation?

Answer 28

• estimate duration of a project computed
• estimate probability of a huge delay
• establish the contingency to reduce the risk to an acceptable level

-

Question 29

Whar are sources of temporal risk?

Answer 29

• not realistic planning
• estimations from early phase of PJ, based on incomplete info
• too many constraints for an agressive/unurealistics schedule
• too much dependancy on new innovation
• complexity in PJ (coordination of to many subcontractors, suppliers or goverment)
• backward scheduling (late start dates) or to much overlappung
• limited floats

Question 30

What are the Limits of the Network Diagram

Answer 30

-for reliable analysis u need a great amount of AC and use sophisticated logical links

→ data should be about:

• AC attributes
• how attributes change on different AC
• Updating data
• The method does not allow to carry out “Estimation at completion” on the base of actual data

Question 31

What are controversies in the Use of Networks?

Answer 31

• Networks can be too complex
• Poor network construction creates problems
• Networks may be used inappropriatley
• NW pose danger, when contractor creat their own one
• Positive bias exist in P E R T NWs