Maintenance Management in Manufacturing Industries
Published on : Tuesday 05-10-2021
A periodic review of maintenance plans will help the organisation to identify the gaps and redesign the maintenance plan, says Suresh Babu Chigurupalli.
Maintenance management is an important function in manufacturing industries. It helps industries to maintain their resources while optimising time and costs to ensure maximum efficiency of the manufacturing process, the utilities, and related facilities. It is a function that helps to secure a reliable and satisfactory quality of production, safety for employees and protection for the environment.
Ideally, Maintenance Management should employ three levels of planning to determine actions on site. These include:
Strategic Planning: The high-level strategic direction for Operational Business Plan
Tactical Planning: A systematic plan describing the major actions, and in what order, that require to be undertaken to achieve the strategic goals:
a. An MMMP (Maintenance Management Master Plan) document, which describes the major actions and explanations
b. An implementation plan, which sets out the major action workflow. This Project Plan is dynamic and continuously updated and monitored to track progress
c. Training documentation, which gives the information required to communicate and explain the masterplan document
Operational Planning: This is a separate document containing detailed planning describing how each of the major actions from the tactical plan (MMMP) will be executed in the plant.
Maintenance management planning levels
Major actions of all MMMP elements are detailed and tracked on an operational/action plan.
This is to ensure:
i. Clarity of understanding – all employees can see what is planned in what order, so can start preparing sooner
ii. Awareness of progress – all employees can see work progressing or being completed
iii. Understanding of workload between workgroups or departments
iv. Task interactions can be identified easily, and
v. Timely notification of issues affecting performance so intervention can be promptly planned to assist any problem areas to recover.
Maintenance plans shall focus to maximise the life of the equipment, e,g., cleaning, alignment, adjusting, lubrication, etc. The maintenance managers would be most interested in how much time was spent looking after the equipment and therefore reducing the need for intervention than just monitoring the equipment and advertising the need for intervention.
A key objective for the plans should be a trend increase of activities that will maximise the life of the equipment. These activities not only increase OEE (Overall Equipment Effectiveness) but will reduce the need for maintenance spend.
Equipment coding & review
Equipment coding is the most important activity and all equipment must have the codes. Utmost care shall be taken to eliminate the duplicate codes. This will help to capture information and develop the database. The complete cost structure of the equipment, parts and labour costs should be clear for equipment.
Maintenance management shall be addressing issues that will lead to the profitability of the organisation. Cost erodes profit, OEE measurement is very critical, but it is also important to understand where the maintenance cost is being incurred as well as which equipment is consuming the most resources. Only then will a true priority be seen – it may be strategically wise to address an equipment issue that is consuming a lot of resources even though it is lower value in cost or OEE so the time saved can then be used to better analyse the OEE and cost issues. Parts and labour hours must be captured by equipment.
Maintenance management shall focus on developing the first two levels of equipment type and component failure codes. These are necessary to understand what the most problematic issues are across the site. Particular types of equipment such as conveyors, motors and pumps can cause more loss than individual equipment in a department while identifying problematic components such as bearings, hoses and fasteners will affect multiple types of equipment.
The third level of ‘cause’ is valuable at a later date: to get an accurate allocation of Cause, a good RCA will have to be done, and this cannot be done on every issue. Implementing this too soon will make the personnel enter what they think is the cause, and analysis may be misdirected. If done properly, this will, however, identify more common issues such as lubrication fault and alignment.
A commonly suggested fourth level of Remedy is only valuable if the site has a use for summarising Remedy. This is not commonly implemented.
Classify critical equipment
Classification of equipment can be considered by using criteria including frequency of failure, safety, environment and total cost of failure.
With the amount of equipment on industrial sites and the workload involved, it is important to know where to focus the maintenance effort. A clear understanding of the plant is required to ensure the equipment with the largest potential return is addressed first. Many organisations classify equipment criticality based on interruption to production, but this method can result in 80% of the department equipment being critical. It still does not give the technical people an accurate understanding of where they should focus their effort. Everything else being equal, some things cause more productivity loss than others.
Ideal recommended classification
The Classification process is a systematic method designed to give a single classification figure (A – high, B – medium or C – low) to equipment (or units), which considers all factors affecting the impact of failure. The output from this review highlights which equipment needs to be addressed first. This process can be used at any level, depending on the detail required – Departments, Units, Equipment or Failure Modes. This is different to a Criticality Analysis – just because some equipment is critical does not mean it is urgent to be worked on.
Seven factors are considered when determining the classification of equipment or unit. These factors include: Safety, Environment, Quality, Working Shift, Production Impact, Frequency and Cost.
Cost considers the bottom-line cost to the company in the event of a failure, including such things as material, labour, production loss, fines, etc. Each of these factors is given a: 1 – serious impact, 2 – average impact, or 3 – low impact at failure, and the answers follow a logic tree to determine whether the equipment is Class A, B or C.
The output of this process is to highlight the top 20% highest consequence items (Class A) which need to be addressed first, and the lowest 20% of items (Class C) that are not urgent.
Output from the classification process
The classification is the order in which the equipment is reviewed – the review process (e.g., RCM) is the same regardless of the classification value. Class B and C equipment can still have significant consequences if ignored.
As to the benefits of using the classification process, this gives:
a. A clearer understanding of the equipment on the site
b. A clearer understanding of the consequences of equipment failure, and
c. A priority list of equipment on the site to review.
The Classification template is to be developed and the numbering of criticality is to be assigned. Add criticality to maintenance plans to ensure most important are always done first.
The most critical equipment should be identified on the maintenance plans to ensure those are complete. Many reasons may prevent all the PMs from being complete in any given week, but a good target for PM measurement is 100% compliance for Class A equipment. If time is insufficient, the plant personnel should be aware of which PMs will give the lease impact if omitted. Without this criticality on the PMs, important preventive and predictive tasks will be missed. If these are not done, the time spent reviewing and determining the tasks will have been wasted.
On many occasions due to the demand, the plant is not available for the shutdown. This maintenance should be discussed with Operations to identify the consequence of omission – not making the plat available for critical PMs could have an overall worse consequence, but it is up to Maintenance to quantify the benefit of these PMs.
Documented and advertise functions of Class A equipment
With time-limited, it is important to only maintain what the plant requires – it is pointless to over maintain and is ineffective to under maintain. Identifying the required level needs a good understanding of what is required from the equipment, i,e.,
To supply a torque of …Nm at a speed of ….RPM
To operate at less than …Amps
To operate at less than …degrees C
To operate at less than …mm/s vibration
To contain …l of hydraulic oil
To separate entrained air
To filter returning oil to …microns
To cool the fluid to …degrees C
To supply pressure between … and … kPa
To supply flow between … and … l/min
To fill a tank in less than … minutes
To contain the fluid
To operate at less than …degrees C
To operate at less than ….mm/s vibration
Review of the maintenance action plans
A periodic review of maintenance plans will help the organisation to identify the gaps and redesign the maintenance plan. Maintenance actions should be eliminated if they cannot be shown to protect a function, and site personnel must know all the required functions or the equipment may still fail with PMs in place. Identifying actual functions may also guide on what PMs to do – the pump for example either has a flow requirement – which will need a flow gauge to verify – or may have time to fill requirement – in which a timer can be used instead of an expensive gauge.
Sureshbabu Chigurupalli is on the Board of Directors/Operations & Maintenance/Keynote Speaker/Lean Practitioner/Production Management/TPM Practitioner with 26+ years of experience. He is Director (Operations) at Balasore Alloys Limited, Balasore, Odisha. He did his B.Tech.in Instrumentation from Andhra University (1994). He is an enterprising leader & planner with a strong record of contributions in streamlining operations, invigorating businesses, heightening productivity, systems & procedures.
Sureshbabu has achievement-driven professional experience in spearheading entire unit/ plant operations to maintain continuity and match organisational goals through supervising Operations, Quality Control, Production Goals, Automation, Maintenance, Process Improvements, Safety Guidelines, Manpower Development, New Policy/Procedure Guidelines, Resource Allocation and Cost Optimisations. He is leading and managing all plant operations with effective utilisation of all resources and implementing industry best practices such as TPM, Six Sigma, Lean Management & others Business Excellence initiatives that contribute to improve productivity and efficiency. He has exhibited leadership in closely collaborating with numerous Japanese Consultants for implementing TPM to enhance overall plant effectiveness.