Tag ArchivePlanned Maintenance


Model-Based Scheduling

Model-based PPM scheduling has been added to commission requests. The model screen now has a technical tab with a field named Preferred PPM Schedule. When using commission requests, once you select a model, if that model has a preferred PPM schedule then you will be asked if the device should be added to that schedule. If the schedule has a preferred week, then you will also be asked if the first PPM job should be scheduled for that date.

As always , any feedback is welcome


Editing Templates

All e-Quip users probably know that job templates lie at the heart of the automated PPM scheduling mechanism. Broadly speaking, if a PPM schedule is a definition of a set of work instructions which need to be carried out at a specified interval, then a job template is the most common way in which the work instructions are defined. Job templates do have other uses but this is probably the way in which they are most commonly used. The basic idea of preemptive scheduling (see this article for more details) is that whenever a PPM job is completed e-Quip automatically creates a new job, based on a job template, for the next service. This type of scheduling has been a feature of e-Quip since its very first version and works very well, but …

What happens when the work instructions change? It is simple enough to edit a template using the Template Manager, but that only affects how future jobs will be created – what about all of the non-started PPM jobs that were created from the original template. Editing a template will not change these. If the changes do not affect sub-lists (i.e. parts, tests, tasks & checklists) then you must remember to bulk update all non-started jobs created from the template so that they match the new template. This is achievable but is quite awkward:

  1. Find all PPM schedules which reference the job template being edited
  2. Find all non-started PPM jobs for those schedules
  3. Bulk update the jobs to match the template

Sub-lists, however, cannot be handled this way. Suppose that job template defines a checklist with a step “1. Measure the gap between the battery support post and the casing. This should be between 1 mm and 1.5 mm“.  What would happen if the template was edited so that the value being measured changes to “…should be between 1.5 mm and 2.0 mm“? Job bulk update does support sub-lists but it is additive. If you specify a spare part in a job bulk update, that part is added to every job. The same applies to test equipment, tasks & checklists. There isn’t really any other way that bulk update can work. This isn’t going to help us here – we would end up with all jobs containing two checklist items:

1. Measure the gap between the battery support post and the casing. This should be between 1 mm and 1.5 mm

1. Measure the gap between the battery support post and the casing. This should be between 1.5 mm and 2.0 mm

2. …

2. …

3. …

3. …

Clearly not what we want!

As from version 3.3.0, whenever a job is created from a template a link to the source template is saved in the job. If that template is ever editing e-Quip will then look to see if any non-started, active jobs exist that were created from the template. If so, the following message is displayed:


If you click on Yes, then every job (10 in this example) will be updated so that all sub-lists exactly match the template.

Why are only sub-lists updated on the non-started jobs? Every one of those jobs will have an Equipment No and assuming that they are PPM jobs they will also have a job type, priority, planned date, work instructions etc. Some of these (job type, priority, work instructions etc) should obviously match the new template but quite  a few will be different for each job. This would include equipment no, planned date, budget, contract, customer and many, many more. These clearly should remain unchanged – or should they? It’s difficult to think of a situation where an equipment no would appear in a template (although I bet someone somewhere does have just such a template), but a job template referencing a contract is not so unlikely. Similarly, only rarely would templates include a Planned Date but there are situations when this might happen. This makes it virtually impossible for e-Quip to know how to deal with fields other than those which appear in sub-lists. There is no way for the software to determine if a field should be copied from the template (job type, priority etc), copied from the existing job (planned date, equipment no), or copied from the equipment record (contract, budget, customer etc- all of which may have changed since the job was originally created).

One approach would be for us to simply define some rules, such as: fields A, B & C are always copied from the template, fields P, Q & R are always copied from the existing job and fields X, Y & Z are always copied from the equipment record. Rules like this are never a good idea. They might work in some situations but not others and they seldom please everyone. For this reason we have chosen to restrict this feature to sub-lists only, which are, after all the reason that the feature has been added.

If you change the body (i.e. anything other than the sub-lists) of a template, then just use good old-fashioned bulk update to update the non-started jobs.



Missed PPM’s on Anchored Schedules

As from version 3.2 we have added a new feature to improve the handling of planned maintenance when:

a. Anchored schedules are used

b. A PPM is missed (not found or not made available)

c. The device is then found shortly afterwards

The Problem

Suppose that a device is on an anchored 12-monthly PPM schedule and the job planned for 1/1/2015 is closed as NOT FOUND FOR PPM in February 2015. The PPM scheduling mechanism will schedule the next job for 1/1/2016.

Now suppose that the device is found in shortly afterwards, in March 2015 and the open PPM job is closed with a Work End Date of 1/3/2015. This will reschedule the next PPM job, but because the schedule is anchored the planned date will be 1/1/2017 (i.e. 12 months from the planned date of 1/1/2016). This is clearly not desirable as the device will not be scheduled to be serviced in 2016 at all.

Prior to version 3.2 the best solution to this was to edit the Planned Date of the job being closed to 1/1/2015 but this was still not ideal. This approach would schedule the next job for 1/1/2016 which is actually 3 months earlier than necessary. While this alleviates the risk of the device not being when it is actually required it is wasteful of resources.

The Solution

The solution is to make use of the new system option Reschedule as Floating after Missed PPM. This option is enabled using the system options.

1. A PPM job is planned for 1/1/2015. In February the job is closed down as NOT FOUND FOR PPM

2. e-Quip schedules the next job for 1/1/2016

3. In March 2015 the device is found and the job closed down on 15/3/2015

4. The next PPM job is scheduled for 15/3/2016

Notice that the PPM schedule itself is still anchored. This means that from this point onwards the device maintenance is anchored to 15th March

As always, any feedback is welcome