Resource Features

Resource categorization

Resources are classified in several categories: human resources, installation (production lines or production centers), tools (additional equipment used by operations for installation), vehicles, subcontractor, production place.
Several numeric parameters could be specified for each resource (capacity ratio, productivity ratio and tolerance ratio). Each one acts during scheduling operations.

One record is created for each resource.

Each record collects a lot of information used by sched.

Resource Skill

Sched maintains a specific table describing the skills for each resource (humans, engines or tools). There is no limit to the number of skills for one resource.

Sched also provides a convenient way to describe resources by defining resources by skills ( or abilities or qualifications).

Infinite capacity resource

With infinite capacity, the scheduling engine never charges the time cells, but takes account of the resource presence (the capacity) (calendar and open/close days).
If capacity is null for a time cell, the resource is considered absent.

Note that a generic calendar with (conventional id Z ) is always open in sched ; this calendar opens the attached resource 365 days/year, 7/7 days and 24/24 hours in days.

This generic calendar could be useful in several cases.

Fictive Resource – Over capacity tolerance

A resource can be qualified with a fictive level.

This notion is interesting to evaluate the missing resources (and skills) to obtain an expected placement.

During scheduling process, time slices cells for each retained resource must have enough capacity. If not, all operations (or processes) are moved forward.

This move could be caused by the absence of only one resource (or many) or one skill (or many).

In some cases, a low level resource absence could be accepted (the manager could probably find in the workshop a qualified resource to fill up the hole).

The over capacity tolerance is accepted by sched in two ways.

First the tolerance ratio attached to each resource could be adapted with care. Mentioning 15% for example will tell to sched to add 15% to each capacity of each time cell for the resource.

Another method is opening fictive resources.

Fictive resources are resources (generally human resources) described as normal resources used; only when sched doesn’t not find any other available resource to achieve a task.

Resource association exclusion table

Sched provides the way to avoid several resources association during a time process. This is useful when operators are excluded to work on a specific installation or environment; or to avoid that two’multi-skilled ‘operators work in the same team ...

Resources Capacity, productivity and tolerance ratios

It might be interesting to attach 3 ratios to each resource.

The over capacity tolerance ratio has been described before.

The Productivity ratio could be useful when standard process time is too optimistic.

The ratio between the forecast consuming time and the real consuming time gives a relevant production ratio.

According to the activity the difference could reach over 20%

Scheduling as to take care of this factor, usually the lost time could be affected to specific resources.

In this case the productivity ratio could be mentioned for resources. In that case all charge times will be increased by x% (the ratio) when the resource is retained.

The consequence is that total process time will be increased by x% of the nominal time cells all over the time line when a resource (with productivity ratio mentioned ) is retained ; of course additional time is computed according to the lowest productivity ratio.

The time in process remains unchanged.

Note: a similar ratio can be given for each process.

The capacity ratio is a convenient way to add capacity to one resource all over the time line without modifying the attached calendar.

Resources generic calendar

For each resource users define the appropriate generic calendar; the resource time line will be built on it.

A new generic calendar is open according to usual open/closed days, working hours and work shifts
Additional Open and closing days; additional open and closing hours in a day could be added specifically for one resource.

All absence/presence out of the normal working hours are collected and coded specifically (code and reason).

Exceptional event

Sched provides a very practical way to describe overtime for a resource without modifying the attached generic calendar.

This method could be used to remove capacity for a short period of time (repairing, maintenance without creation of specific orders).

With sched you can close but also open days and/or time periods outside the normal time line generated by a generic calendar.

Modeling time – Horizon – Time Cells

Sched builds the same time line for every resource.

The time line has no limit, and could be from some days to years according to your process.

A time line is limited to a defined horizon and divided into cells, the time cells.

The time slices could be defined in 15’ , hours and days.

Horizon and time slices are variable according to the production environment and context.

Each time slice is called a time cell in sched.

Each time cell for each resource contains several counters (theoretical capacity, used capacity and cumulated charge are the main ones; a few other ones are used) .

Note that several operations could be affected to the same time cell for the same resource, if the cell capacity is not empty.

If the time slice is one hour ,the last operation of one process and first (or more) operation of another process could be positioned in the same cell.

The value of each counter in each cell is always justified by a lot of inscriptions..

Building the resource time line

Each time cell (all along the time line) for each resource is computed by the system according to several rules.

A few generic calendars are created specifically for each class of resources engines, operators, vehicle, and working hours or work shifts

Each general calendar is composed of days; each day could be opened or closed for the production.

If a day is opened, open hours in the day are defined according to the working hours and the work shifts.

For each generic calendar a typical time frame is provided (from one week to 7 weeks) which could be easily adapted and reproduced from any day.