2.2. Functional Requirements

2.2.1. Display Functions

There are three standard display methods that have been requested for KPlato. These methods are:

• Spreadsheet: The list of tasks and subtasks are displayed down the left column of the spreadsheet. The columns across the spreadsheet display the various attributes of those tasks.

• PERT Chart: The tasks and their relationships are displayed in a network diagram. The task interdependencies are indicated by the connections on the diagram.

• GANTT Chart: The tasks are displayed on a page as bars. The page is laid out such that time increases as you move across the page. A task's start time/date is indicated by the point on the page the bar starts, and it's duration is indicated by the length of the bar.

It is expected that the spreadsheet view will be the first one developed for KPlato.

2.2.2. Work Breakdown Structure

The Work Breakdown Structure is a hierarchical list of the tasks that are defined for a project. It consists of a list of tasks in a project. The tasks are numbered in a fashion that reflects the structure of the project.

The WBS is defined as a tree structure. The following terminology is often used when discussing the WBS:

• Project: the project is the root node in the WBS tree.

• Task: a task is any node in the WBS tree other than the root node.

• Subtask: a subtask is any node in the WBS tree that has a task as its parent.

• Terminal Node: a terminal node is any task that does not have any subtasks defined for it.

• Subproject: a subproject is any subtree that exists in multiple Work Breakdown Structures.

This vocabulary is used in the application domain to describe specific relationships in the WBS tree and does not necessarily reflect a difference in the way the item is represented internally.

Insert sample wbs

2.2.3. Resources

A resource is something that is required to perform a task and is limited in time and quantity. Resource assignment has the following constraints:

1. All terminal nodes in the WBS tree must have a resource allocated to them.

2. Resources may only be allocated to tasks that are terminal nodes.

A resource is defined by its schedule of availability. This is currently being viewed as a calendar that lists the days and hours within a day that the resource is available over a certain period of time.

In order to assign a resource to a task the following additional estimates must be made:

1. The effort required from the resource.

2. The risk associated with the resource.

All these items are taken into account to determine the estimated duration of a task (described in the next section).

How do we take into account related resources? (e.g. computer equipment that is being used by the employee). Break this down into two separate tasks that end on the same date?

2.2.4. Relationships

Tasks have relationships defined between them, indicating how they are related to each other. The common relationships are as follows:

• Finish-Start: task B cannot start until task A has finished

• Finish-Finish: task B cannot finish until task A has finished

• Start-Start: task B cannot start until task A has started

In addition each relationship can have a lag defined for it, which indicates a minimum time that must elapse between the linked items (e.g. task B cannot finish until at least 3 days after task A has finished)

2.2.5. Calculations

KPlato should be able to perform the calculations described in the following sections.

2.2.5.1. Task Duration

Durations are calculated for a task based on the resources assigned to it. The following factors need to be taken into account:

1. The effort required from each resource

2. The risk associated with the resource/task pairing

3. The availability schedule of each resource

4. The other task commitments of resources

[Jim Sabatke]  Allow task durations to be calculated from the following columns:         "Optimistic Hours"             "Pessimistic Hours"           "Expected Hours"            "Risk"             "Duration"         The "Duration" would be calculated like:         "Risk" = Low        Duration = (OH + 4EH +PH) / 6         "Risk" = High      Duration = (OH + 4EH + 2PH) / 7         "Risk" = None      OH = EH = PH = "Duration"           If Duration is entered, then OH, PH, EH all will be set to  "Duration" and "Risk = None"