Subproject division and schedule
In the process of building a large-scale geographic information system, because various departments are involved, functions and data are in a variety of forms, and different software and hardware platforms are involved, it is necessary at the beginning of the implementation of the project. make a plan to coordinate all aspects of the problem. Usually, the most important part of the plan is the arrangement of the sub-project and the schedule of the whole project.
Divide subitems
The determination of sub-projects is one of the most important links in the design process of the whole GIS system. The reasonable formulation of sub-tasks makes the details of all aspects not to be omitted to ensure the whole plan, budget and quality are secured. Subprojects should include not only technical tasks, but also various non-technical tasks, including management, support and so on. When dividing sub-projects, we can divide them from top to bottom according to the six levels of the whole project, task, sub-project, specific work and steps. Table 15-4 lists common GIS project tasks。
Table 15-4: Common GIS Project Tasks [Gong Peng]
Project planning
Pilot project
Database generation
Data output
|
GIS analysis
Application system development
Others
|
|---|---|
Principles and representation of schedule arrangement
Project scheduling is a process that managers need to complete before they enter the design and implementation phases. Each sub-project should be scheduled in time and sequence. Before scheduling, it is necessary to estimate the time required for each activity from start to finish. Secondly, the factors to be considered include the dependence between activities (one must be completed before the next one can be carried out) and the earliest start-end time and the latest start-end time of each activity (e.g., 120 days for the whole project and 30 days for an activity). Days, then its latest start time is 90 days. The plan should be flexible and can be adjusted accordingly according to the changes. In addition, to ensure that participants have enough time to complete various tasks, it is a more realistic way to arrange a certain “mobile time” between tasks。
Milestone Chart, Gantt Chart, CPM-Critical Path Method and Wall Paper Method are commonly used to represent project progress。
Milestone Chart
Milestone Chart is applicable to small-scale projects and can be used to draft project plans. It treats major tasks as a phase, which is clear and easy to use. The disadvantage is that it can not express the relationship between tasks and has poor control over the project process. The sample of this method is given in Table 5。
Table 15-5: Milestone Chart
Task coding |
Primary contents |
Responsible group |
Estimated completion date |
Actual finishing date |
Gantt chart
Gantt chart method, also known as histogram method and histogram method, is currently used in many ways. It is easy to show the time and sequence of activities, but it can not describe the impact relationship and is difficult to control complex projects. Figure 15-6 is an example of Gantt chart method。
Task contents and code |
1998(Quarter) |
1999(Quarter) |
||||||
One |
Two |
Three |
Four |
One |
Two |
Three |
Four |
|
Project planning Pilot project
Application software development
Project management |
Fig. 15-6: Gantt chart to show project progress
Critical path method
Critical path method expresses the dual relationship between the sequence and constraints of tasks in a project, which is suitable for schedule control of large and complex projects, it is used for critical path method requires managers to have a clear understanding of the relationship between sub-projects. The shortcoming is not flexible enough and is cumbersome to make。
Wallpaper method
Wallpaper method is mainly applied to projects with more people participating. The characteristic is to directly arrange tasks for each specific person. When the wallpaper method is used to make the progress of a project, it is necessary to have the participation of relevant project personnel at the beginning so as to facilitate the initiative of the project。
In order to make the schedule more reasonable, computer software can be used to assist in scheduling。