Preventive Maintenance

Preventive Maintenance automates the regular maintenance of assets and space as follows:

Work Processes are maintenance procedures, which each list the Trade required and the estimated hours.
Work Schedules each specify an asset or space, a Work Process to be performed on it, and parameters for generating Work Dates.
Work Dates are generated from Work Schedules.
Work Orders are generated from Work Dates, each having Work Requests with Issued status.

These Work Requests are then processed in the same way as those of Corrective Maintenance.

Database

The Maintenance module database has the following additional structure for Preventive maintenance:

This diagram omits reference tables, described below.


`work_process`		Work Processes
`work_process_id`		Process Code - unique mnemonic code to identify the process and its frequency.
`process_type`		Process Type - the items to process, one of: `EQ` for Equipment. `SP` for Space (sites, buildings, floors, rooms).
`description`		Process Description
`work_trade_id`		Trade Code - the trade required to perform the process.
`work_person_id`		Tradesperson / Contractor Code - the tradesperson / contractor that will be assigned to Work Requests for this process by default.
`work_process_ids_to_suppress`		Work Processes to Suppress - a comma-separated list of `work_process_id` values for other processes whose work dates should be omitted if they occur in the same week as those for this process (for example, if there are 3 month and annual processes, the annual process can specify that coincident 3 month processes should be omitted).
`enabled`		Enabled - if not the default of `Y` (Yes), the process will not be included in Available Processes in the Work Processes / Generate Work Schedules page.
`hours_req`		Hours Required - the estimated hours required to perform the process.
`comment`		Comment

`work_schedule`		Work Schedules
`work_schedule_id`		Work Schedule Code - Autoincrement.
`work_process_id`		Work Process Code - the process to be performed.
`eq_id`		Equipment Code - for the `EQ` Process Type, the equipment item on which the process is to be performed.
`site_id`		Site Code - for the `EQ` Process Type, the the equipment item's site, otherwise the site on which the process is to be performed.
`bl_id`		Building Code - for the `EQ` Process Type, the the equipment item's building, otherwise the building on which the process is to be performed.
`fl_id`		Floor Code - for the `EQ` Process Type, the the equipment item's floor, otherwise the floor on which the process is to be performed.
`rm_id`		Room Code - for the `EQ` Process Type, the the equipment item's room, otherwise the room on which the process is to be performed.
`date_first_todo`		Date for First Process - with the interval, this defines the dates on which the process will be performed for Fixed scheduling.
`interval_type`		Interval Type - the interval between performing the process, one of: `d` Days. `ww` Weeks. `m` Months. `q` Quarters. `yyyy` Years. `h` Hours.
`interval_freq`		Current Frequency - the field `interval_N` value to use (e.g. a value of 2 specifies use of the `interval_2` value). This provides a memory of alternative intervals to use.
`fixed`		Fixed or Floating - specifies how dates on which the process will be performed are calculated, one of: `0` (Fixed) - relative to the Date for First Process. `1` (Floating) - relative to the completion date of the previous Work Order for this process. (Currently not supported - Floating is processed as Fixed).
`interval_1`		Freq. 1 Interval - if Current Frequency is 1, with Interval Type this specifies the frequency at which the process is performed (e.g. `3` with `m` means every 3 months).
`interval_2`		Freq. 2 Interval - if Current Frequency is 2, as above.
`work_schedule_group_id`		Work Schedule Group - an optional group of which the schedule is a member. Available as a filter in Work Dates / Generate Work Orders, and for use in reports.

`work_date`		Work Dates
`work_schedule_id`		Work Schedule Code - the schedule, therefore the item and the process to be performed on it.
`date_todo`		Process Date - the date on which the item is to be processed.
`work_order_id`		Work Order Code - the Work Order, set by Work Dates / Generate Work Orders. NOTE that: this field must have no Foreign Key constraint, to permit archival of Work Orders when their Work Requests are Closed or Cancelled. this field may have as reference table (`sisfm_flds.ref_table`) a database view which is a union of tables `work_order` and `work_order_archive`, for use by reports.
`enabled`		Enabled - if not the default of `Y` (Yes), this date will not be processed by Work Dates / Generate Work Orders.

REFERENCE TABLES

`work_schedule_group`		Work Schedule Groups
`work_schedule_group_id`		Work Schedule Group - unique mnemonic code to identify a group that Work Schedules may belong to.
`description`		Description - a description of the group.