Learning Outcome 8

Question 1

8.1 Describe ways to create and maintain a schedule

Answer 1

• Time scheduling is a collection of techniques used to develop and present schedules which show when work within a project is planned to be performed
• Before a schedule can be created, it’s essential to have a WBS, an effort estimate for each tasks and a resource list with availability
• Scheduling software products exist but the concepts and basics should be understood before use
• The project schedule is created by defining all of the work tasks to be performed, taking into account their relationships, estimated durations and resources required
• The steps are: identifying tasks from WBS, estimating duration (Effort) of each task), determining logical relationships between tasks (dependencies), carrying out optimisation of the schedule and testing the logic, assigning resources required to carry out work, checking defined schedule means target success criteria, baselining the schedule and monitoring
• Dependencies can be shown on a network diagram. A Gantt chart can show dependencies and scheduling. A histogram can show resource requirements.

Question 2

8.2 Differentiate between critical path and critical chain as scheduling techniques

Answer 2

• There are two principles types of scheduling: critical path and critical chain
• The critical path approach places the emphasis on the activities in a project and understanding the shortest time to complete activities in a logical order. To do this, dependencies need to be agreed. This allows a precedence network to be determined. Then estimates of duration can be made (three point estimate if possible - best, worst, most likely). The critical path is the sequence of activities through the precedence network from start to finish. The sum of their duration is the overall duration. Some activities float (happen simultaneously with other longer aspects) and can be extended without extending overall duration of project. When using an iterative life cycle, a timebox approach is used (using Gantt chart) rather than estimating time and cost (a fixed period of time with determined resources during which scope is performed to the best quality possiblle)
• The critical chain method (resource critical path) places the emphasis on the resources in a project rather than activities. It wants to keep resources at a constant utilisation. When resources are estimated , there are various aspects that will influence how that activity will ultimately be performed, its duration and effect on successors (skills, abilities, tools). If a task finishes early, usually someone tries to over-deliver or catch up on something unrealted. If it’s late, it has an affect on succeeding activities. The benefit of early completion is lost where late has to be absorbed. The critical chain attempts to rebalance this. The simplest critical chain approach takes the estimated duration for each activity and reduces it by 50% to create a time contingency. Rather than added to the task, it’s added as a buffer to a critical chain of activities. For it to work, resources need to be available which requires work between team and stakeholders. It depends on a culture which understand estimates and the role of the buffer. Focus is on maximum productivity on set task rather than deadlines. Rate of the consumption of the buffer is used to control project schedule (reported to stakeholders using fever chart).

Question 3

8.3 Describe how resources are categorised and allocated to a linear life cycle schedule

Answer 3

• Resources are all the labour and non-labour items required to undertake the scope of work (labour, equipment, materials, facilities)
• Each resource may drive project pace by constraining output that can be achieved (a resource cap will determine how much work can be done to that point). When resources constrain project delivery, they are known as critical resources. Also consideration of relationhship between resources and logistics (e.g. materials have to be stored).
• Linear: when using a linear life cycle, the assumption is that the schedule is planned initially and all resources are available when required. If, reviewing the schedule, this is not the case, resource management techniques like levelling and smoothing can be applied.

Question 4

8.4 Describe how resources are categorised and allocated to an iterative life cycle schedule

Answer 4

• Resources are all the labour and non-labour items required to undertake the scope of work (labour, equipment, materials, facilities)
• Each resource may drive project pace by constraining output that can be achieved (a resource cap will determine how much work can be done to that point). When resources constrain project delivery, they are known as critical resources. Also consideration of relationhship between resources and logistics (e.g. materials have to be stored).
• Iterative: Requirements are prioritised and implemented with pre-allocated resources for that time period (and scope and quality therefore will vary). If all scope must be delivered to a specified quality, an extension is required.

Question 5

8.5 Differentiate between resource smoothing and resource levelling

Answer 5

Resource levelling: when resources are limited by time is more flexible. Could redefine scope of activities to be undertaken by a specific resource and moved to another. Redefine the specification (without change to quality of product). Increase task duration to reduce overall resource requirements. Increase resources on earlier work so peaks are avoided later down the line. Moving activities not on critical path to reduce demand at peak times.

Resource smoothing: when time is more important than cost. Could add more resources to complete a task and aiming for smooth use of resources without peaks and troughs, optimising flow of resources from one task to another). Resource smoothing will only help duration of project if applied to critical path activities (Wouldn’t have an impact if applied to those with float). Redefinition of order of work may be required (moving things to happen simultaneously, for example).

Question 6

8.6 Differentiate between cost planning for iterative life cycles and for linear life cycles

Answer 6

• Cost planning is an essential part of the project management process. A forceast cost is not enough alone for project control. Project manaers need to understand where costs fall in their schedule to manage resource demand, supplier payments and funding requirements
• Need to understand when certain costs will occur and whether they are fixed or repeat and have variation
• Iterative: in an iterative life cycle, the release of funds may be more frequent due to short intervals of work produced and close work with sponsor
• Linear: funds may only be released at decision gates, where current costds are understood and future costs approved