WklGantt

A Gantt chart for Access forms: the tasks from a table appear as a hierarchical datasheet on the left, and their bars, dependencies, and milestones on a timeline on the right. It supports a working calendar, manual or automatic scheduling, and the critical path. It can do everything `WklTreeList` does: columns, cell editors, formatting, and export.

• Create a project plan

• How to: Plan tasks with dependencies
• How to: Export the chart
• How to: Exchange plans with Microsoft Project
• How to: Save and restore the view (Layout also saves the zoom level, splitter position, and visible period)

+- List1 -------------------------------------------------------------------------------+
| Task              | Start       | Finish      |#| Week 41, 10/5/2026     | Week 42    |
|                   |             |             |#| 05 06 07 08 09 10 11   | 12 13 [1]  |
+-------------------+-------------+-------------+#+------------------------+------------+
| v Project   [2]   | 10/5/2026   | 10/13/2026  |#| ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀  |
|     Planning      | 10/5/2026   | 10/6/2026   |#| ████─┐                 [3]          |
|     Building      | 10/7/2026   | 10/9/2026   |#|      └►██▓▓▓▓ Miller    [4]         |
|     Acceptance    | 10/12/2026  | 10/12/2026  |#|             ░░  └──────►◆  [5]      |
+-------------------+-------------+-------------+#+------------------------+------------+
                                                 [6]

• Tasks from your tables: start, finish or duration, progress, milestone, constraint, deadline, and baseline are fields of the task records (StartField, FinishField, …); summary tasks are records that have child records.
• Dependencies in a separate table (DependencySource) or as text in the task record (PredecessorsField, for example 3FS+2;5SS): finish-to-start, start-to-start, finish-to-finish, and start-to-finish, with lag.
• Working calendar: working days and hours (WorkDays, WorkHours), nonworking days from a table (HolidaySource), and durations in working days or hours (DurationUnit).
• Scheduling: manual (nothing moves; violated rules are reported) or automatic (dependent tasks move as soon as their dependencies and constraints allow); critical path and slack.
• Editing like in project management tools: drag bars, their ends, and the progress handle; draw and delete dependencies; link, unlink, split, and mark progress from the shortcut menu or with Ctrl+F2. Every change raises Before and After events and is written in a single transaction.
• Split tasks and resources with assignments (as text or in tables).
• Output: Excel with the timeline as real cells, image, PDF, and Microsoft Project XML.
• Import from Microsoft Project, matched against the existing records, with a preview dialog.
• Designer with the Tasks, Dependencies, Resources, Calendar and scheduling, and Timeline pages and a live preview of the real data.
• UI Automation: for screen readers and test tools, the task list is a data grid and the timeline is a list of bars with their dates and progress.

Your data stays in your tables. The chart reads task records, dependencies, segments, resources, and nonworking days from the sources it's bound to, and writes every change back (AutoSave). It doesn't keep a schedule of its own: requery the form, and the chart shows what's in the tables.

Dates in the schedule and in the table. Dates are stored the way Access stores them: when the chart schedules in days, the finish is the task's last working day, with no time. Internally, the schedule uses points in time with an exclusive end; the conversion is fixed and identical for every read and write.

Manual or automatic. ScheduleMode determines how a change affects other tasks. In manual mode, a task that starts too early for its dependency stays where it is and shows up in Violations and as a red arrow. In automatic mode, dependent tasks move; a task you move by hand gets a “Start No Earlier Than” constraint, just as in Microsoft Project. Tasks without dependencies or constraints never move, so the first scheduling pass doesn't reshuffle existing data.

Summary tasks. A record that has child records is a summary task. Its start, finish, and progress (weighted by duration) are calculated; UpdateSummaries writes them to its record so queries and reports can use them.

Changes by the user and by code. Dragging, the shortcut menu, and the date and progress columns raise BeforeTaskChange, BeforeLinkAdd, and the matching After events, where VBA can adjust or cancel the change. The same changes made in code (SetTaskDates, LinkTasks, TaskProgress, ImportFromProject without the dialog) raise none of these events.

• How to: Install the released package
• How to: Deploy an application with WKL controls to user PCs
• What the per-user registration writes

• The timeline shows no bars
• Importing a Project file adds the tasks again

• API reference: WklGantt

• WklTreeList overview: its how-to guides apply here too