APLIKASI LEAN SIX-SIGMA UNTUK MENGURANGI PEMBOROSAN DI BAGIAN PACKAGING SEMEN

Hasil observasi di PT. Holcim Indonesia Tbk, pabrik Cilacap, didapati banyaknya pemborosan di bagian pengepakan semen, termasuk banyaknya produk cacat kemasan, sehingga banyak semen tercecer dan harus mengulangi proses pengepakan. Penelitian ini dilakukan untuk mengidentifikasi pemborosan selama proses pengepakan menggunakan pendekatan lean manufacturing dengan value stream mapping. Sementara tingkat kualitas dianalisis dengan metode six-sigma. Penyebab kecacatan produk dianalisis dengan fish-bone diagram. Failure Mode and Effect Analysis (FMEA) digunakan untuk merancang ususlan perbaikan. Pemborosan yang teridentifikasi meliputi : transportation, motion, waiting, over processing, dan defect. Usulan perbaikan untuk mengurangi pemborosan yaitu dengan penggabungan stasiun penimbangan dan stasiun pemeriksaan, sehingga memberikan estimasi peningkatan process cycle effisiensi dari 39,1% menjadi 46,69. Sedangkan upaya untuk mengurangi cacat produk dilakukan dengan perawatan preventif mesin packer.

The potential effectiveness of lean construction principles in reducing construction process waste: an input-output model

With the spread of a culture of waste reduction in the construction industry, the traditional management system has become insufficient, so it has become crucial to implement more innovative techniques to improve the performance of this sector. In response to this need, Lean Construction (LC), which is the global reference of a production system with the minimum of waste generation, has attracted several construction companies all over the world. However, previous studies indicate that are several implementation scenarios that differ from one company to another according to their own understanding of the Lean Construction concept. In this paper, the authors attempt to fill this gap by proposing an original input-output model that aims at clarifying the main conceptual basis of Lean Construction philosophy, as well as establishing interactions between the main principles of this concept and all sources of wastes that exist in the construction industry. The proposed model shows nine main principles: customer focus, supply, continuous improvement, waste elimination, people involvement, planning and scheduling, quality, standardization and transparency. In addition, the practical relationships between those principles and nine sources of waste (transportation, motion, inventory, waiting, overproduction, defects, over-processing, unused employee creativity, and work Accidents) have been analysed.

Nonlinear Control of Flexural–Torsional Vibrations of a Rotating Thin-Walled Composite Beam

In this paper, the effectiveness of a saturation control strategy in suppressing vibration of a rotating composite thin walled beam is studied. The mathematical model of the flexible beam takes into account a shear deformation effect, a warping function, a centrifugal force and the Coriolis acceleration. To extend the generality of the proposed formulation an inertia of the hub is also considered. Adaptive capability of the beam is achieved through the implementation of the saturation control algorithm. Within the performed tests, the discussed control strategy is applied for different magnitudes of flexural–torsional vibration modes resulting from different orientations of beam laminate-reinforcing fiber’s. The obtained results prove the applied nonlinear control to be the effective method for beam vibration suppression in near-by resonance zones for all studied cases. Parametric studies considered different rotating speeds of the system. It is shown that the vibration of the beam can be suppressed to similar levels independently of the transportation motion rotating speed. However, significant differences in the width of vibration suppression zones are observed.

Automated driving, technical approach with motion control architecture

Automated Driving is the key technology for greater safety, comfort and efficiency in personal transportation. Motion Control ensures that the high-level behavior planning is carried out properly even in case of failures and disturbances. Based on the flatness property a feedforward trajectory control is obtained to ensure lateral motion along prescribed trajectories. An optimal state feedback control reduces the effects of disturbances like side wind or road bank to a minimum.