maintainability-planning and scheduling

7/29/2019 Maintainability-Planning and Scheduling

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Maintainability

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What is Maintainability ?The U.S. Department of Defense publication, MIL-HDBK-470A, dated 4

August 1997,

The ability of an item to be retained in, or restored to, a specified

condition when maintenance is performed by personnel having specified

skill levels, using prescribed procedures and resources, at each prescribed

level of maintenance and repair

Wikipedia (for telecommunications)

A characteristic of design and installation, expressed as the probability

that an item will be retained or restored to a specified condition within agiven period of time, when maintenance is performed in accordance with

prescribed procedures and resources.

The ease with which maintenance of a functional unit can be performed in

accordance with prescribed requirements.

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Downtime

Uptime UptimeDowntime

Time of FailureRun-down

Preparationand/or delay

ActiveMaintenance time

Waiting and/or delay

Ramp-up

State

Time

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Maintainability is About

Design

Logistic

Location / Space Work Process

Work Scope

Leadership

Skill

Communication Technology

Policy

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Maintainability MetricsMean Time to Repair(MTTR) The arithmetic average of themaintenance cycle times for the

individual maintenance actions of a

system (excludes preventivemaintenance)

Mean Down Time(MDT) The mean or average time that a systemis not operational due to repair or

preventive maintenance. This includeslogistics and administrative delays.

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Planning and

Scheduling

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Total Maintenance Cost RatioPlanned Maintenance Minimum CostUnplanned Maintenance 1.5 Times Minimum CostBreakdown Maintenance 3-9 Times Minimum Cost

You can hear unplanned maintenance by listening to craftspeople

Whos available ?Wheres the parts?

How did they do it last time ?

Wheres the lock-out?How late is the order now ?

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Planning and Scheduling improve

Productivity13%

Personal 10%Clerical15%

Waiting forJobs

22%

Travel time andStores

10%

Waiting forInstructions

30%Production Work

50%Production Work

Reduce by30%

60% Increase

inProductivity

BeforeControlled

Maintenance

After

Controlled

Maintenance 8


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Planning and Scheduling

Planning and Estimating Jobs 20-30%Scheduling 15-25%Purchasing and Expediting Parts 20-30%Other Duties 25-35%

A poll of planner/schedulers taken over a 10 year period

indicated the following breakdown of an averageworkday

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Work

identification

Work Planning

Work

Scheduling

Work

Assignment

Work

Execution

Work Analysis

Specify

Source

Order

Store

Control

Use

Analyse

Equipment

Control

Equipment

Arrangement

Bills of Material

Repairables

Delivery ofMaterials to

Specific Drop site

Reporting

Requisition

Receiving

Report

F

eedback

Inspection

Predictive

Preventive

CBM

Corrective

LubricationRepair

Feedba

ck

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Planningis the allocation of needed resources and the

sequence in which they are needed, to allow

an essential activity to be performed in the

shortest time or at the least cost.

Purpose

To ensure that all the resources and information

necessary to do the job are accounted for

Failing to Plan = Planning to Fail 11


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Resources Labor & Crew Size & Skill

Materials , Parts & Supplies

Tools Support Equipment

Contracted (Outside) Services

Time

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What does a job plan contain ?

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Work Planning

A Process in which work is

Estimated

Assigned resources

Given detailed safety procedures

Given work procedures

Documented and interfaced with the scheduling

element

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Planning and Estimating Methods

Construction Planning and Estimating

Method Time Measurement

Planning Thought Process Estimates Based on Past Performance

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Planning Thought ProcessWhat must happen

first on this job ?

Who must do thisstep ?

How many people arerequired ?

What Parts , Material

, or Supplies will beneeded ?

Is any supportequipment required ?How long will it take ?

What must happennext on this job ?

Inspect theequipment and site

What safety

/environmental

precaution arerequired ?

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Estimating using past performance

Problem

Completed hours charged to

historical records may be inaccurate

History records may not document

all parts used on the job History records do not capture other

resources

Historical record may not capture

outside services Closure notes on historical records

do not clarify actual work

performed

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Improving the History Record

Write WO for all maintenance activities

Charge parts and materials to WO only

Charge outside services to a WO

Provide a means to capture undocumented

resources

Enlist meaningful comments on the work

performed

Use WO to update equipment database

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Standard Job Plan

A Planner should never

have to plan the same job

twice

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Scheduling

Is the assignment ofmany planned jobs into adefined period of time in order to optimize

the use of the resources within their

constraints

placing an identified need for work on a

formal work list at least two days prior to the

day that the work is to begin

A Backlog of work is required23


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Resource Constraints

Fixed Amount of Labor

Limited or Special Skills

Space Physical Properties

Rules and Regulations

Money

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Scheduling

Can be based on a work order backlog of jobsthat are not linked to each other but have

different importance (entity criticality , WO

priority and WO class) Can be based on activities or work orders

from a project , turnaround or shutdown

where job importance and the timing of whenthey are done in relation to each other is

critical

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The Criteria utilized

Work group net capacity / Calendar

Work order priority and cycle time of the work

order

Opportunities of an equipment shutdown +

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Priority System

The Drawbacks of not Clearly Defining Priorities

Wasted maintenance man-hours on tasks of

low relative importance

Critical tasks being lost in maintenance

backlog

Dissatisfied operations customers

Lack of faith in the effectiveness of the

maintenance delivery functions

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Scheduling

A Schedule is a communication document

Operation

Store

Supervisor

Contractors

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To Schedule Work

Identify Preventive maintenance and corrective backlog by:

Equipment

Priority

Due Date Determine Availability of skills and resources

Look at productions equipment operating Schedules for the

period and attempt to match their plan

Balance the work list against the resources (both internal & external)

Agree to schedule with operations , modify as required prior

to issue to the work shop

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Weekly ScheduleDeveloped at the weekly scheduling meeting

Input from

Maintenance first-line supervision

Scheduler Planner

Maintenance Manager

Operations Representatives

Provide maintenance supervision with work orders

The work orders selected are based on cycle time and

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Schedule Development

Planner/Scheduler distributes backlog

Operations reviews list picks work

Maintenance reviews list picks work

Engineering provides list of work required

Maintenance provides craft availability

Planner triggers PMs List returned to Planner/Scheduler with

selection

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Planner/Scheduler builds tentative schedule

PMs due

Operations picks

Maintenance picks

Engineering requirements

Planner/Scheduler adds activities from

backlog until craft availability is full

Highest priority oldest cycle time

Reviewed and agreed to at weekly meeting

(Friday Afternoon)

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Weekly Schedules

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Daily Schedule

Built by maintenance first-line supervisors

Uses the work orders identified on the weekly

schedule

Includes assigned crafts personnel

Urgent work orders placed on schedule for the

following day

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Daily schedule review meeting

10 minute meeting held daily in the afternoon

Attended by

Maintenance first line supervision

Maintenance scheduler

Engineering

Review the status of the work scheduled for that day

Review the work scheduled for the following day

Insert any urgent work requests that ready for

scheduling

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Fixed agenda

Safety issues

Past 24 hours

Next 24 hours including any urgent work added

All problem solving off-line

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Daily Schedules

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Contractors

Contractors are generally brought in for maintenance on 3

occasions

Special skills are required that are not represented in the

normal maintenance work force.

The maintenance backlog is excessive and critical work is

not being completed on time. Contractors are used to

work the backlog down

A unique situation (Shutdown or turnaround) requires

crewing levels far above the facility maintenance work

force.

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Best Practice

There is a well defined , comprehensiveschedule of maintenance activities for all

areas of the facility

Compliance to Pm/PdM schedule is > 95% Overall schedule compliance is >90%

A minimum of 45% of available personnel are

scheduled for planned

80% of available manpower is scheduled on a

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Weekly meetings for creating the upcoming

weeks work schedule

All meetings attended by Maintenance ,

Operations and Engineering department

representatives for the area.

100% available manpower is scheduled on a

daily basis

Daily schedule review meeting held to confirm

upcoming days work

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Performance Measurement

Indicator FormulaBacklog Backlog hours

Hours in a work week x No. of Available CraftspeoplePlanned &

ScheduleCompliance

Schedule hours actually worked

Total Hours Scheduled% EmergencyWork Total Emergency worked (hours)Total hours workedOvertime Total overtime worked (hours)

Total hours worked

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Conclusion

Key Roles and Relationships

Planner = what to do

Scheduler = when to do it

Supervisor = who to do it

Craftsperson = How to do it

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