MME80001 Resource Planning: Facility Lyout Design and AON Network

Introduction

The design and layout of a manufacturing facility is a hugely important component of the overall operations of a business both in terms of production process effectiveness maximization and meeting employee needs. The principal objective of a layout is to ensure that smooth work flows of information and materials through the system. A facility in this context refers to the space where the activities of the business take place; its design and layout have a great impact on the how the work is done. The facility layout refers to the arrangement of different manufacturing aspects in a manner that is appropriate so that the desired production results are achieved. To achieve this, consideration is made for the final product, the available space, and convenience of operations as well as the safety of the users ('Inc', 2017). This paper discusses and generates a suitable design for a precast manufacturing unit for one-off and less routine operations and for routine operations, based on sound design principles and justifications provided. The paper will begin the design by laying out the objectives for the facility, this is followed by a discussion of the factors that affect the layout of the facility and then a design for the facility proposed. A suitable technique is chosen for the layout design using the most fitting type of facility layouts (Baykasoglu, Dereli and Sabuncu, 2006)

Part 1: Objectives for the facility layout design

To accord optimal space for the organization of equipment and facilitate goods movement so that a safe and comfortable work environment is achieved

• To ensure order in production geared a single objective
• To promote the safety of workers and plants/ equipment
• To reduce the movement of raw materials, workers, and equipment
• To increase the capacity for production of the organization
• To facilitate change or extension in the layout so as to accommodate technology upgrades or new related product lines (Baykasoglu, Dereli and Sabuncu, 2006)

To achieve the above objectives for the precast manufacturing facility, the factors that can affect the layout of the facility are also considered. The factors vary from industry to industry; all objectives must be considered and space allocation must be optimal. The design for the facility layout is done following the basic design principles of flexibility, space utilization, and capital. The precast manufacturing facility will basically assemble materials to make the precast and so the most suitable layout design technique is line balancing (Becker and Scholl, 2006). Line balancing is a strategy used to ensure production lines remain flexible enough such that it can absorb internal and external irregularities. Line balancing can be achieved in two ways; static balance which pertains to long term differences in capacity over many hours; when there is static imbalance, the result is underutilization of machines, workstations, and people (Patil, 2011).  Dynamic balance refers to short term capacity differences, such as over a period of a few minutes or at most, hours. Dynamic imbalances arise from product mix variations and changes in the work time that are unrelated to the product mix (Özcan et al., 2010). Product line stability tends to have fixed assignments for labor; when balancing equipment, this design has made attempts to make sure every piece of equipment in a work cell has similar amounts of work. While the conventional wisdom is to maximize the utilization of all the available equipment, such an approach is usually counterproductive since high utilization is accompanied by high inventory.

Facility layout type

For the precast manufacture, the chosen facility layout is the combination layout; the Combination Layout is a layout type that combines the product and process layouts and therefore enjoys the benefits of both layout types (Levy and Kalman, 2001). The combination layout has been chosen because precast concrete will be manufactured in different sizes and types; the combination layout is suitable for such types of products, according to Benjaafar and Sheikhzadeh (2000). The machinery in combination layout are arranged in a process layout; however, the process grouping is arranged sequentially so that various sizes and types of precast concrete is manufactured; this is one of the main strengths of combination layout design, according to Levy and Kalman, (2001), (Heragu, 2008). The operations sequence will however remain the same for the different product sizes and variety. The layout below is therefore prosed based on the above analysis and justifications;

The process begins with the raw materials where the rebar is laid out; it is on the rebar that the concrete mix will be poured.  The rebar is first cut and then taken to the next step where it is bent to fit the precast shape/ type and then fixed. The rebar is then transferred to the casting bed where it is placed. Meanwhile, as the rebar is being made and shaped, the concrete mixing process starts simultaneously where cement, sand or any other fine aggregates, gravel or other coarse aggregates such as coarse sand and admixtures are mixed together. The mixture is then taken to the concrete batching plants where water is added as per the requirement and based on desired mixture rations for all materials. The finished concrete mixture is then transferred to the casting bed. So at the casting bed, the fixed rebar is already set; the concrete is then cast onto the rebar (also in the casting bed) and allowed to set. After the concrete is mixed or is in the process of being mixed, cast in items and finishing items are prepared and mixed together and then transferred to the casting bed. The mixture is then transferred to the casting bed and added to the cast concrete and rebar.  The form work can be adjusted before the rebar is placed. The concrete cast with rebar and finishing items  is then ready and is left to cure for some time (days). Once the precast concrete has cured or is curing, the form work is then de-molded.  The de-molded form work is then transferred to the form work yard for cleaning, ready for the next product. When the concrete has cured, then we have the precast component ready for shipping to the customer; the whole process is detailed in the diagram below;

Part 2

The AON (activity on node) network for repairing the roads and bridges is depicted below;

The activity details are shown in the table below;

 
To manage this project and allocate resources, the traditional; PERT and CRM approaches can be used; however, these have the limitation in that they assume the availability of resources in the project network is unlimited. However, this is not usually the case because in real life projects, the resource and time requirements for activities are limited and should be given consideration when developing network schedules. The resources cannot be simultaneously satisfied; hence the need for tradeoffs since the project schedule becomes longer if the resource base is small.  Allocating resources makes possible the movement of from a given state to another; the progress of a project in its initial state can be defined as Si and the future state is defined as Sf and a such, three scenarios can occur;

• Further progress is achieved by moving from Sf to Si (Sf>Si)
• Progress can be stagnant between the initial and future states so that Sf=Si
• There may be regression of progress from the initial to the future state so that Sf<Si (Adedeji, 1993)

In allocating resources for the repair projects, strategies are developed to determine the next desirable project state as resource criticality and availability determines the assigning of activities to resources to enable progress of the project from one state to the next.  The strategy for allocating resources is to allocate activity G 2 technical staff members and allocate activity A two technical staff members. This is because they start concurrently; activity G requires 4 technical staff while A requires 2; however, to proceed to activity B, A must be completed, hence the allocation of all required technical staff; however, even if activity G will take longer, there is a lot of activities that must be undertaken before the next activity needs to be done, so even with few technical staff, the objective will still be achieved. A does not require special equipment so will be allocated all the needed fuel (50 liters). A will get the required 1 support staff as L does not require a support staff but requires A to be completed on time before it can commence. B takes 3 days and requires 4 technical staff; but will be allocated 3 technical staff and L which will be allocated 1 technical staff instead of 2 because there is a long duration before the next activity after L (K) starts; meanwhile B, C, D and E must be completed. L will be allocated the requisite 100 liters fuel along with 1 special equipment and 5 epoxy materials.  

C will be allocated all the 2 technical staff and 1 support staff because it must be completed before D can commence; however, it will get 35 liters so the work is done within the two days. D will be given the 1 support and 1 technical staff along with 20 liters of fuel while E will get 50 liters fuel plus 3 technical staff and 2 support staff; E must be completed before F can start but K must also be done concurrently and it must be completed also before F can start. H will be given the 6 technical staff because E is a bottleneck to procession of the activities to F; both H and K must be completed and so a lot more resources will be allocated to H and K as well as E; if H and K are completed on time, still F cannot proceed before E is complete. K will get 2 technical staff and 1 support staff because it requires two days and does not use special equipment. H will be allocated 180 liters because it uses two specialized equipment; H, E, and K must be completed on time before F can be started. The resources are allocated so to achieve leveling; G and L can have some resources expendable because of the longer time duration required before the next task can be started. F will be allocated all the necessary resources of 20 liters, 6 technical staff, and 3 support staff; no special equipment or epoxy is needed but it must be done within 2 days; all technical staff will be available as well as support staff to be used in task F.

Resources can be optimized through real time tracking to ensure key performance indices and performance targets are met. Another strategy is to modify group and individual calendars and list of tasks to reflect changing priorities. Re- allocation and resource optimization will also help balance workloads and hence optimize resources while task estimates analysis is also helpful in resource optimization. All team members must be given a 360 degree project visibility to understand how their contributions impact the entire project. Creating business rules will also optimize resources as they remind team members of overdue time sheets (Bender, 2010), (Meredith and Mantel, 2012)

References

Adedeji, b. (1993). Activity-resource assignments using critical resource diagramming. [online] Pmi.org. Available at: https://www.pmi.org/learning/library/activity-resource-assignments-resource-diagramming-5631 [Accessed 6 Apr. 2017].

Baykasoglu, A., Dereli, T. and Sabuncu, I. (2006). An ant colony algorithm for solving budget constrained and unconstrained dynamic facility layout problems. Omega, 34(4), pp.385-396.

Becker, C. and Scholl, A. (2006). A survey on problems and methods in generalized assembly line balancing. European Journal of Operational Research, 168(3), pp.694-715.

Bender, M. (2010). A manager's guide to project management. 1st ed. Upper Saddle River, N.J.: FT Press.

Benjaafar, S. and Sheikhzadeh, M. (2000). Design of flexible plant layouts. IIE Transactions, 32(4), pp.309-322.

Hentenryck, P. (2006). Principles and Practice of Constraint Programming - CP 2002. 1st ed. Berlin, Heidelberg: Springer-Verlag Berlin Heidelberg.

Heragu, S. (2008). Facilities design. 3rd ed. Boca raton: Taylor and Francis.

'Inc', (2017). Facility Layout and Design. [online] Inc.com. Available at: https://www.inc.com/encyclopedia/facility-layout-and-design.html [Accessed 6 Apr. 2017].

Levy, A. and Kalman, H. (2001). Handbook of conveying and handling of particulate solids. 1st ed. Amsterdam: Elsevier.

Meredith, J. and Mantel, S. (2012). Project management. 1st ed. Hoboken, N.J: Wiley.

Özcan, U., Çerçio?lu, H., Gökçen, H. and Toklu, B. (2010). Balancing and sequencing of parallel mixed-model assembly lines. International Journal of Production Research, 48(17), pp.5089-5113.

Patil, R. (2011). Production Line Balancing - Learnaboutgmp. [online] Learnaboutgmp. Available at: https://learnaboutgmp.com/production-line-balancing/ [Accessed 6 Apr. 2017].